PHARMACOLOGIA. (continued 5)

Infusum Rosæ Compositum. L.E.D. This is an infusion of the petals of the red rose, rendered astringent and refrigerant,^[538] by the addition of dilute sulphuric acid. By referring to the Dynameter, it will be seen that f℥j; does not contain more than four and a half minims of dilute acid, which are equivalent to three-sevenths of a minim of the strong concentrated acid. Wherever therefore we expect any advantage from this latter ingredient, the quantity must be increased by extemporaneous addition. Incompatibles. All those bodies which are decomposed by the sulphuric acid; the sulphates of iron and zinc do not immediately alter the infusion, but they slowly decompose it, producing precipitates of a dark colour. Dr. Clarke of Cambridge detected iron in the petals;^[539] may not the presence of this metal enhance the tonic powers of the infusion? It affords a most elegant vehicle for the exhibition of cathartic salts.

Infusum Sennæ Compositum. L.E.D. A pint of water will take up the active matter of ℥j of senna, but nothing beyond that proportion; hence there is an unnecessary waste in the London process. The quantity of infusion directed to be made at one time, is also injudicious, since by simple exposure to the air for only a few hours, in consequence of the powerful affinity of its extractive matter for oxygen, a yellow precipitate takes place, and the infusion loses its purgative quality, and excites tormina in the bowels; in preparing it therefore, we see the necessity of conducting the process in covered vessels, and of making only such a portion as may be required for immediate use; indeed, notwithstanding every precaution, the extractive will to a certain extent become oxidized, and the infusion have a tendency to gripe.^[540] Dr. Cullen used to say that Senna was one of the best purgatives, if it could only be divested of its griping quality; this however he was unable to obviate, because he was not aware of its cause, 401and therefore conjoined it with various aromatics, instead of those salts^[541] which might be capable of increasing the solubility of its oxidized extractive, or the purgative activity of the infusion; see page 150, and 161. Soluble tartar and alkaline salts are its most useful adjuncts; it is however rarely prescribed in practice without the addition of other cathartics. (Form. 70, 76, 90.) Sydenham’s favourite “potio cathartica lenitiva,” consisted of an infusion of tamarinds, senna leaves, and rhubarb, with the addition of manna and syrup of roses. The addition of tamarinds renders the infusion more grateful but less active; when made with bohea tea, it is in a great degree deprived of its nauseous taste; a decoction of guaiacum increases its powers, and is said at the same time to render it milder. Bitters also very considerably exalt its efficacy, see page 153. A pint of the infusion with a drachm of jalap forms an excellent combination for a purgative enema. Incompatibles. The infusion is disturbed by strong acids; lime water; nitrate of silver; oxy-muriate of mercury; acetate of lead; tartarized antimony; and by an infusion of yellow cinchona. Dose, f℥j-f℥ij.

IPECACUANHÆ RADIX. L.E.D.

(Callicocca^[542] Ipecacuanha.) Ipecacuanha.

Qualities. Form, tortuous pieces of the thickness of a goose-quill, surrounded by numerous prominent rings, separated by deep grooves. This root, when powdered, has a faint disagreeable odour, and a bitter sub-acrid taste. Chemical Composition. The late researches of M. M. Majendie and Pelletier have detected the existence of a new vegetable proximate principle in this root, to which ipecacuan is indebted for its emetic properties; they have, accordingly, denominated it Emetine.^[543] It assumes the form of transparent brownish red scales, which are nearly inodorous, but have a slightly bitter, acrid, but not nauseous taste. Emetine is decomposed by a heat higher than that of boiling water; it is insoluble in water, in every proportion, without undergoing the least change; and in a moist atmosphere it deliquesces; it is also soluble in alcohol, but not in æther; nitric acid dissolves it, but at the same time decomposes it; dilute sulphuric acid has no action on it; muriatic acid and phosphoric acid dissolve it, without altering its nature; acetic acid dissolves it with great facility; corrosive sublimate precipitates it from its solutions, but tartarized antimony has no 402effect upon them; gallic acid, the infusion of galls, and acetate of lead, precipitate it. A grain excites violent vomiting, followed by sleep, and the patient awakes in perfect health! It exerts also a specific action on the lungs and mucous membrane of the intestinal canal; when taken in an overdose, its action can be instantly paralysed by a decoction of galls. There seems to be no great advantage in substituting this body for the ordinary powder of Ipecacuanha, except perhaps that its taste being much less offensive, it may very easily be given to children.^[544] Emetine appears to exist in Ipecacuanha, combined in the following manner, emetine 16, oils 2, wax 6, gum 10, starch 40, woody fibre 20.

Since the discovery of Emetine, whose properties are described above, Pelletier has extended his researches into its composition and nature; and he has lately been enabled to state that this body, which in conjunction with Majendie, he had formerly announced as “a new vegetable proximate principle,” turns out to be a compound of a peculiar alkaline basis, which may be called Emeta, and some acid, together with an admixture of colouring matter; when compared with Emetine, it is what white crystallized sugar is to moist sugar. Its ultimate elements are oxygen, hydrogen and carbon; it is a white and friable substance, and unlike Emetin, is not altered by exposure to air; it is slightly bitter, and very sparingly soluble in water; with the mineral acids it forms salts, from whose solutions the infusion of galls throws down white and flocculent precipitates; the alcoholic solution of Emeta acts upon vegetable colour as an alkali.

Medicinal Uses of Ipecacuan. It is unquestionably the most valuable of the vegetable emetics, and in cases where the stomach is irritable it is to be preferred to Tartarized Antimony, and it is also less liable to act upon the bowels. In the form of decoction (made by boiling three drachms of the bruised root in a quart of water down to a pint) it has been found serviceable as an enema in Dysentery, and internal piles. Incompatible Substances. All vegetable astringents, as infusion of galls, &c. vegetable acids, especially the acetic, weaken its power; Dr. Irvine found that grs. xxx, administered in f℥ij of vinegar, produced only some loose stools. Forms of Exhibition. The form of powder is most energetic, although the vinous solution is both active and convenient. Dose. The medicinal operation of this substance varies with its dose, thus grs. x to ʒss act as an emetic; (Form: 65,) grs. j to ij, as an expectorant, (Form: 134, 138,)and in still smaller doses it proves stomachic and diaphoretic; by combination with opium, this latter quality becomes more powerful, (Form: 28, 130.) The primary effect of this medicine is that of stimulating the stomach, and it is equally obvious that its secondary ones depend on the numerous sympathies of other parts with the organs of digestion. The action of this remedy upon the pulmonary organs is extremely interesting; it would seem that in certain conditions of these organs, attended with a dry, hard cough, it promotes expectoration, while in affections attended 403with an inordinate secretion of mucus, it as certainly represses it, and acts the part of an astringent. In dysentery, and chronic diarrhœa, its astringent power is also very decided. Form: 58. When combined with cathartics it aids and accelerates their operation; Form: 84. In Hemorrhage from the lungs and uterus, it is decidedly useful, when administered in such doses as to excite a slight degree of nausea, by which the force of the circulation is controlled; I have usually combined it, for such a purpose, with the Acetate of lead in Hæmopthysis; and Bergius relates a case of violent uterine hæmorrhage which was successfully treated by giving half a grain every half hour. In certain forms of Dyspepsia it proves highly beneficial, when administered as proposed by Daubenton, in doses just sufficient to excite a slight sensation of vermicular motion of the stomach, without carrying it to the point of nausea, which may be generally effected by half a grain three times a day. Its peculiar nauseous taste is completely covered by the addition of powdered Gum Arabic. Solubility. Alcohol takes up four parts in twenty of Ipecacuan; proof spirit six and a half; and boiling water rather more than eight parts; one pint of good sherry wine will dissolve about 100 grains; the alcoholic is more emetic than the aqueous solution; decoction destroys the emetic property of the root. Officinal Prep. Pulvis Ipecacuanhæ comp: L.E.D. Vinum Ipecac. L.E.D.^[545] The powder is liable to become inert by exposure to air and light. The root is refractory, and is reduced to powder with difficulty, unless a few drops of oil, or an almond or two, be previously added. It is a curious fact that the effluvia of this root occasion in some persons the most distressing sensations of suffocation. I am acquainted with a lady, who is constantly seized with a violent dyspnœa, whenever the powder of Ipecacuan is brought into her presence. Adulterations. There are several varieties of Ipecacuan to be found in the market, which it is important to distinguish; viz. 1, The brown variety, which is the best, containing sixteen per cent. of emetin; 2, the grey variety, with fourteen per cent. of emetin; 3, the white variety, with only five of emetin. The two former varieties are those usually met with, being imported into this country in bales from Rio Janeiro; the brown is distinguished from the grey, in being more wrinkled; the white variety has no wrinkles whatever. We are informed by Decandolle that the genuine root is frequently mixed with those of violets, Apocynæ, Euphorbia, &c. It is also sometimes mixed with the roots of several species of Ionidum.

JALAPÆ RADIX. L.E.D. (Convolvulus Jalapa.)

Jalap.

Qualities. This root is pulverulent, furnishing a powder of a pale brownish yellow colour. Odour, peculiar; Taste, sweetish and slightly pungent. Chemical Composition. Resin, gum, extractive, fecula, lignin, and some salts. The combination of the three first principles appears requisite for the production of its full cathartic effect. The gum has been supposed to possess diuretic properties. Very lately a saline principle has been obtained from Jalap by Mr. Hume, jun.: but I am not aware that its medicinal properties have been ascertained. It is procured 404by macerating the powdered root for twelve or fourteen days in acetic acid, by which a solution is obtained, which must be filtered, and then saturated with ammonia; the mixture is to be shaken violently, when a sabulous deposit will take place, and a few crystals be collected on the sides of the vessel; both of these must be collected, and washed in distilled water; and then redissolved in concentrated acetic acid, and reprecipitated by ammonia added in excess. By which means, small white acicular crystals are thrown down, to which the name of Jalapine has been given. Solubility. Proof spirit is its appropriate menstruum. Med. Uses. It is a cathartic of a stimulating description, acting principally upon the colon, and, notwithstanding the tormina it may sometimes induce, it is no less safe than efficacious; as a hydragogue purgative it has been greatly extolled, but for such a purpose it will answer better in combination, as in Form. 73. Its action is said to be promoted by the addition of Ipecacuan, or tartarized antimony. (Form. 84.) In dropsy its union with super-tartrate of potass is calculated to promote its beneficial operation. Forms of Exhibition. That of powder is the most eligible, especially when combined with some other powdered substance: pulverization increases its activity, see Pulveres. Van Swieten advised it to be pulverised, and mixed with sugar, and a small quantity of some aromatic. The addition of Soap is supposed to render its operation much milder, and the Prussian Pharmacopœia contains a formula for such a combination, which is said to operate mildly and promptly. To this preparation the name Sapo Jalapinus^[546] is given. Dose, grs. x to ʒss. Officinal Preparations. Pulv. Jalap. comp. E. Extract. Jalap. L.E.D. Tinct. Jalap. L.E.D. Tinct. Sennæ comp. E. (B). Adulterations. Briony root is sometimes mixed with that of jalap, but it may be easily distinguished by its paler colour and less compact texture; and by not easily burning at the flame of a candle. When the teredo has attacked it, it should be rejected.

JUGLANS CINEREA.

Butternut.

Cortex.

[The Butternut tree is to be found in almost every part of the United States. The inner bark is the part used in medicine. It yields, by analysis, a large quantity of soluble matter, principally of the extractive kind. Water extracts its virtues, and the Extract, which is the form in which it is employed, has long been known and used in this country as an excellent Cathartic. To obviate habitual costiveness, it is one of the best articles that can be used. By the addition of Calomel, its powers as an active Cathartic may be greatly increased. The proper season for gathering the bark for medicinal purposes is in the months of May and June. The dose of the Extract is from 10 to 30 grains.]

405JUNIPERI BACCÆ ET CACUMINA. L.E.D.

(Juniperus Communis.)

Juniper Berries and Tops.

The principal constituents of these berries are mucilage, sugar, and volatile oil; in the latter of which their diuretic virtues reside. Forms of Exhibition. That of an infusion, made with ℥ij of the berries, to oj of hot water. Unless pains however are taken, by strong contusion, to bruise and break the seeds, the preparation will contain but little of the juniper flavour. The bruised berries may be also triturated with sugar or some neutral salt, and be thus exhibited in substance, Dose ℈j to ℈ij. Officinal Preparations. Oleum Junip. L.E.D. Spirit. Junip. Co. L.E.D. The taste and diuretic properties of Hollands depend upon this oil; English gin is flavoured by oil of turpentine.

KINO. L.E.D. Kino.

(Pterocarpus Erinacea.^[547] Extractum. L. Eucalypti Resiniferi. Succus Concretus. E. Butea Frondosa. D.)

There is very considerable obscurity with regard to the history and chemical constitution of this substance; three varieties of it are met with in the shops, viz. 1. African Kino, which bears the highest price, and has all the appearance of a natural production, slender twigs being often intermixed in its substance; it is of a reddish brown colour, and has a bitterish astringent taste. 2. Botany Bay Kino, has also the aspect of a natural production, it is in more solid masses than the former species, is less brittle (for it contains a very small proportion of resin) and, with its astringency, has a disagreeable sweetish taste. 3. Jamaica Kino, this is the one most commonly met with; it has the appearance of a dry extract, is in small fragments, of a colour more nearly approaching to black than that of the others, and has an astringent and slightly bitter taste. There is also a fourth variety mentioned, viz. the East India or Amboyna, but this does not appear to differ from the African variety. Chemical Composition. In all the varieties the predominant principles are tannin and extractive. Solubility. The best menstruum is diluted alcohol. Incompatible Substances, vide Gallæ. Mr. Thomson also states a fact which I have reason to consider quite correct, that the alkalies destroy the astringent properties of kino. All the varieties are soluble in solutions of pure potass and ammonia, and no precipitation takes place on the addition of water. Medicinal Uses. It is principally employed as an astringent, but from its liability to vary in strength, it has been very generally superseded by Catechu.^[548] Forms of Exhibition. Either in substance or in the form 406of watery infusion, or in that of tincture. Dose, grs. x to ʒss. Officinal Preparations. Tinct. Kino. L.E.D. Elect. Catechu. E.D. Pulvis Alum. co. E.

KRAMERIÆ RADIX. L. (Krameria Triandra Radix.)

Rhatany.

This root, although it has been for some time employed in medicine, has only lately found its way into the Materia Medica of the London Pharmacopœia. Its extract, which was some years ago imported into this country, is supposed to have been employed for giving astringency to Port wine. According to recent analysis the root contains a peculiar modification of Tannin, with only a trace of Gallic acid; Gum; Fecula; and certain salts of Lime. It may be used either in decoction, or tincture, the latter of which may be made by dissolving two ounces of the root in a pint of proof spirit. In all its forms it is eminently astringent. I have used it with much success in Leucorrhæa, and in uterine hemorrhages. The extract may be distinguished from Kino, to which it bears a great resemblance in appearance and taste, by being very fusible by heat, whereas Kino does not possess that character.

LICHEN. L.E.D. (Lichen Islandicus.) Lichen.

Iceland Liverwort. Iceland Moss.

Qualities. Odour, none; Taste, mucilaginous and bitter. Solubility. The effect of water upon this vegetable substance is materially modified by temperature; if cold, the lichen absorbs nearly its own weight by maceration, but gives out to the menstruum little or none of its virtues; if the water be warm, it soon acquires a bitter impregnation; by ebullition, a decoction is obtained, which, as it cools, gelatinizes. See Decoct. Lichen. Chemical Composition. Proust has shewn by analysis that 100 parts of this moss contain 64 parts of a substance bearing some analogy to vegetable gluten, 33 of matter, soluble in hot water, and resembling starch, and 3 parts of a bitter principle. Medicinal Uses. This vegetable was introduced to the notice of the profession by Linnæus, who recommended its decoction, as having been administered with great success for coughs in Sweden. Upon its introduction into this country, its patrons bestowed so many extravagant eulogiums upon its powers, that the less sanguine practitioner at once abandoned its use in disgust, and it fell into unmerited disrepute. It would be idle to speak of its specific effects in phthisis; but, as a demulcent, it is certainly very superior to the mucilaginous mixtures in ordinary use, and its simple bitter principle at the same time tends to produce a tonic effect, which is frequently desirable in the debilitated condition which characterizes the latter stages of this disease. There are circumstances, 407however, which may render the removal of the bitter advantageous; in which case, maceration in successive waters, or in a weak alkaline ley, as recommended by Westring, will be found to answer the intended purpose. Officinal Preparation. Decoct. Lichen. Island. E. D. Sir Alexander Crichton has offered some observations upon the genuineness of this article which deserve attention. He says that there are two varieties in the market; the best of which has a horny texture, and yields a bitter mucilage. It is that which comes from Iceland, Norway, Sweden, and Finland. The inferior kind has a membranous texture, and yields little bitter or mucilage in comparison with the former. Where it comes from he knows not, but he suspects it to be British, as it is much cheaper than the other.

LIMONES. L.E.D. (Citrus Medica. Baccæ.)

Lemons.

Succus—The Juice consists of Citric acid, mucilage, extractive matter, and small portions of sugar and water. Specific gravity, 1·0384. It may be preserved for a considerable length of time, by covering its surface with fixed oil.

Its use in making saline draughts has been already noticed, see Acid. Citric. Its principal medicinal value consists in its antiscorbutic^[549] virtues; indeed it may be fairly asserted that this disease, so peculiarly incident to a sea life, has been nearly eradicated by the juice of lemons. Sir Gilbert Blane, in speaking of its efficacy, asserts that “those only who have made themselves acquainted with the early part of the Naval history of this country, or those who have perused the interesting, popular, and eloquent narrative of Commodore Anson’s voyage, can duly appreciate the value of this simple remedy.” Lemonade, as a beverage in putrid diseases, was first introduced by the French physicians in the beginning of the 17th century, and about the year 1660, an Italian from Florence, having learnt a process of freezing confectionary, conceived the happy idea of converting such beverage into ice. This found a ready sale, and was the occasion of so great an increase in the number of sellers of Lemonade, that in the year 1676, the Lemonadiers of Paris were formed into a company, and received a patent from the government.

Cortex—The Rind or Peel is composed of two distinct parts; the exterior, which contains glands, filled with a fragrant volatile oil, upon which all its properties depend, and the interior coat, which is tasteless and indigestible. The flavour may be obtained by rubbing lump sugar upon it, which will imbibe the oil, and if it be then dried by a very gentle heat, may be preserved unimpaired for any length of time, and will be preferable to the volatile oil obtained by distillation, for the fire generally imparts an unpleasant or empyreumatic flavour.^[550]

It has been already stated, that “the different parts of the same plant have frequently very different properties.” The Lemon offers a good example of this fact, for its juice is acid, its seeds bitter, and its peel aromatic.

408LINIMENTA. L.E.D. Liniments.

These are external applications, having the consistence of oil or balsam. If we except the Liniment. Æruginis, all the officinal liniments are decomposed by the substances which are incompatible with soaps.

Linimentum Æruginis. L. Oxymel Æruginis. P.L. 1787. Mel Ægyptiacum. P.L. 1745. Unguentum Ægyptiacum. P.L. 1720. Diluted with water, it has been recommended as a gargle in venereal ulcerations, but its use is hazardous; it is a detergent escharotic preparation.

Linimentum Ammoniæ Fortius. L. Oleum Ammoniatum. E. Linimentum Ammoniæ. D. It consists of liquor ammoniæ one part, olive oil two parts, (oil eight parts, E.D.) The alkali forms with the oil a soap, which is held dissolved by the water in the liquor ammoniæ. Is an excellent rubefacient, and penetrating liniment.

Linimentum Ammoniæ Sub-carbonatis. L. Linimentum Ammoniæ. P.L. 1787. Linimentum Volatile. P.L. 1745. The carbonic acid prevents the perfect formation of soap in this liniment; unlike the former one, therefore, it deposits the soapy matter on standing. It is much less stimulating than the preceding one.

Linimentum Calcis. E.D. Oil and lime water, equal parts. This is an earthy soap, formed by the combination of lime and oil; the soapy matter separates on standing, it should therefore be extemporaneous. In cases of burns and scalds where the cuticle has been destroyed, it is an advantageous application.

Linimentum Camphoræ. L. Oleum Camphoratum. E.D. Camphor one, olive oil four parts. It is a simple solution of camphor in fixed oil, and forms a very useful embrocation to sprains, bruises, glandular swellings, and in rheumatic affections.

Linimentum Camphoræ compositum. L. Camphor two, liquor ammoniæ six, spirits of lavender sixteen parts. It is highly stimulating.^[551]

Linimentum Hydrargyri. L. A pound of this liniment contains nearly ℥iv of mercury; it affects the mouth more rapidly than strong mercurial ointment, although it will be seen by the Medicinal Dynameter to contain less Mercury. This effect is to be attributed to the stimulating properties of its adjuncts, viz. Camphor and Ammonia.

Linimentum Saponis compositum. L. Hard soap iij, camphor j, spirit of rosemary xvj parts. It is a stimulant and anodyne application, and in local pains opium may be advantageously added to it. It is commonly used under the name of Opodeldoc.^[552] See Sapo.

Linimentum Terebinthinæ. This liniment was introduced by Mr. Kentish of Newcastle, as a dressing to recent burns, which he continued until the eschars became loose.

409LINUM CATHARTICUM. L.D. Purging Flax.

The qualities of this plant reside in extractive matter, hence water extracts, but long decoction injures them. Medicinal Uses. It is strongly purgative. Forms of Exhibition. ʒij of the dried herb infused in oj of boiling water. Dose, f℥ij.

LINI USITATISSIMI SEMINA. L.E.D.

Linseed, or Common Flax Seed.

These seeds contain a large proportion of mucilage, and one-sixth of their weight of fixed oil; the former of which resides principally in the cuticle, the latter, in the parenchymatous portion of the seed; by infusion in boiling water, a clear, colourless, inodorous, and nearly insipid mucilage is obtained; ℥ss of the unbruised seed is sufficient for oj of water; cold water does not extract any mucilage from them when unbruised; the farina of the seeds is well adapted for cataplasms. Officinal Prep. Infus. Lini Comp: L. Oleum Lini. L. E. D.

LIQUOR ALUMINIS COMPOSITUS. L.

Aqua Aluminosa Bateana. P. L. 1745.

This is a compound solution of alum and sulphate of zinc; a fluid-ounce containing about seven grains of each ingredient, it is powerfully astringent, and is successfully used as a detergent lotion to old ulcers; as a collyrium, or as an injection in gleet and fluor albus; it will also often answer in removing chilblains, and in curing slight excoriations.

LIQUOR AMMONIÆ. L. Aqua Ammoniæ. E.

Aqua Ammoniæ Causticæ. D.

Solution of Ammonia.

Qualities. Form, a limpid, colourless fluid; specific gravity, ·960, or f℥j weighs about 438 grs. Odour, strong and pungent; Taste, extremely caustic. Chemical Composition. A solution of ammoniacal gas in water, which varies considerably in strength in the different pharmacopœias. When prepared according to the London and Edinburgh Colleges, it contains nearly 25 per cent. of ammonia, whereas the Dublin preparation does not contain more than 16. Solvent Powers. It is an active solvent of many vegetable principles, e. g. oils, resins, &c. With alcohol it unites in every proportion; it assists the oxidizement of copper and zinc, and dissolves many of the metallic oxides. Med. Uses. Stimulant, rubefacient, and antacid. Forms of Exhibition. In milk, or any liquid vehicle; if in decoctions, or infusions, they must be previously cooled; for at 130° the ammonia will escape in the form of gas. Dose, ♏︎x to xxx. Officinal Prep. Linimentum Ammoniæ. L.D. Oleum Ammon. E. Spir. Ammoniæ. L. Spir. Ammoniæ comp. L. Spir. Ammon. succinat. L. Liniment. Camphor. comp. L. Adulterations. The presence 410of other salts in the solution may be discovered by saturating a portion with pure nitric acid, and applying the test for sulphuric acid, (Barytes) and that for muriatic acid, (Nitrate of Silver.) Carbonic acid is detected by its effervescing with acids, or by its forming with lime water, a precipitate, soluble with effervescence in nitric acid; it ought to be free from all fetor; its strength can only be determined by taking its specific gravity. It should be preserved in well closed bottles, and their dimensions should be small, for when in large vessels it often becomes carbonated before it is half used.

LIQUOR AMMONIÆ ACETATIS. L. Aqua Acetatis Ammoniæ. E.D.

Solution of Acetate of Ammonia.

olim, Spirit of Mindererus.

This preparation is a solution of the neutral acetate of ammonia, with a proportion of carbonic acid diffused through it; it is made by saturating the sub-carbonate of ammonia with distilled vinegar, for which purpose it will generally be found that ℥j of the alkali will saturate oiss of the vinegar; since, however, the quantity of acid in distilled vinegar as well the strength of the ammonia, are liable to constant variation, the exact point of neutralization should be ascertained by the alternate application of litmus and turmeric papers; for if the proportions be not accurately adjusted, some of the metallic salts, especially those of antimony, which are often prescribed in conjunction with it, are decomposed, and thus rendered inefficacious; and on this account an excess of alkali is to be feared more than that of acid. This preparation is also not unfrequently employed as a collyrium, when much serious mischief may arise from the carbonate of ammonia predominating. It has been already stated that a very minute proportion of extractive matter is rendered sensible on the addition of an alkali; hence this preparation frequently derives from the vinegar a brown hue, which may be removed by filtering the solution through a little well burnt charcoal. It also deserves notice that the presence of a trace of copper, derived from the copper cocks through which the vinegar has passed, will impart a brown tinge, whilst in larger quantities this metal yields a blue colour with ammonia. Incompatible Substances. Acids; fixed alkalies; alum; lime water; sulphate of magnesia; corrosive sublimate; nitrate of silver; and the sulphates of zinc, copper, and iron. Acetate of lead produces also a copious precipitation, but this depends upon the presence of the carbonic acid diffused through the solution, which decomposes the salt and forms an insoluble carbonate of lead. Magnesia likewise, contrary to what might be supposed, decomposes the solution and renders it pungent, from the extrication of ammoniacal gas; this phenomenon depends upon the magnesia forming a triple acetate with one part of the ammonia, and setting the remainder at liberty. Med. Uses. When assisted by warmth and plentiful dilution, it is an excellent diaphoretic, and produces its effects without quickening the circulation: (Form: 117, 126,) by keeping the surface of the body cool, its action is determined to the kidneys, and it proves diuretic, especially when combined with remedies of a similar tendency. (Form: 111.) Dose, fʒiv to 411fʒxij. Externally it furnishes a lotion, valuable as a refrigerant, especially when combined with some spirituous preparation. See Form: 148.

LIQUOR AMMONIÆ SUB-CARBONATIS. L.

Solutio Sub-Carbonatis Ammoniæ. E.

Aqua Carbonatis Ammoniæ. D.

This is merely a solution of the solid sub-carbonate in distilled water, see Ammoniæ Sub-carbonas. Dose, fʒss to fʒj in any bland liquid. Adulterations. There is frequently a deficient quantity of the sub-carbonate in solution, its pungency being kept up by the addition of liquor ammoniæ; this may be discovered by shaking it with twice its bulk of alcohol, when a coagulum of considerable density should occur, the absence of which will denote the sophistication of the article. Its specific gravity should be 1·150. The Incompatibles are those enumerated under the history of Ammoniæ Sub-carbonas.

LIQUOR ARSENICALIS. L.

Solutio Arsenicalis. E.

This is a solution of the Arsenite of Potass, coloured and flavoured by the Compound Spirit of Lavender, fʒj of which contains gr. ½ of arsenious acid. It was introduced into practice by Dr. Fowler of Stafford, as a substitute for the empirical remedy known by the name of “The Tasteless Ague Drop.” It is a powerful tonic, and has been very successfully administered in the cure of intermittent and remittent fevers, periodical headaches, and as an alterative in many anomalous diseases of the skin. It has been also given, with decided effect, in certain visceral obstructions; its use however is to a great degree empirical, although we may observe, generally, that wherever strong arterial action exists, arsenic will do harm. The addition of a few drops of Vinum Opii is said to render its operation safer and more efficacious. Incompatible Substances. Lime water; nitrate of silver; the salts of copper; hydro-sulphuret of potass, and the infusions and decoctions of bark. Dose, ♏︎iv, gradually increased to ♏︎xxx, twice a day. See Arsenicum Album.

LIQUOR CALCIS. L. Aqua Calcis. E. D.

Lime Water.

It is a saturated solution of lime in water; f℥j of which contains 3/4 of a grain.^[553] Incompatible Substances. All alkaline and metallic salts; 412borates; tartrates; citrates; acids; sulphur; spirituous preparations, and the infusions of all astringent vegetables. It should be kept in close vessels, for if exposed to the air, the lime will attract carbonic acid, and become an insoluble carbonate; the addition of an alkaline carbonate produces the same effect instantaneously.^[554] If animal charcoal be boiled with lime-water, it will precipitate the whole of the lime, an effect which is not produced by charcoal of vegetable origin. Med. Uses. It is an antacid, and is therefore useful in dyspepsia attended with acidity; Form. 149. Mixed with an equal quantity of milk, it furnishes an excellent remedy in infantile complaints connected with bowel affections; it is likewise astringent in leucorrhæa, in the last stages of dysentery, and in protracted diarrhœa. It dissolves also the slimy mucus with which disordered bowels are so generally infested; on account of this latter property, it has been exhibited in calculous affections,^[555] with the view of dissolving the cementing ingredient of the concretion, and thereby of destroying its cohesion: see page 123. Not being very nauseous, it is easily given under any circumstances, and it is not liable to produce that irritability of stomach which frequently attends the long continued use of the fixed alkalies. It also frequently forms the basis of astringent gargles. Lime water moreover affords a successful remedy in certain cutaneous affections, particularly those affecting the face, as Gutta Rosea. Sir G. Blane has also seen some remarkable cures of herpetic complaints of the legs by large doses; he has also employed it with effect as a lotion. Forms of Exhibition. Milk disguises its flavour, without impairing its virtues. Dose, f℥j to f℥vj. Sugar has the curious property of rendering lime more soluble in water. See Saccharum.

413LIQUOR CALCIS MURIATIS. L.D.

Solution of Muriate of Lime.

This solution is said to be tonic and deobstruent, and to have been advantageously given in scrofula. It has also been found useful in Urticaria, and several other forms of cutaneous disease. Incompatibles. Sulphuric acid, and the Sulphates; the fixed alkalies and their carbonates; ammonia produces no change in the solution, but its carbonate decomposes it, and precipitates carbonate of lime. Dose, ♏︎xx to fʒij.

LIQUOR CUPRI AMMONIATI. L.

Solution of Ammoniated Copper.

This is a simple solution of the salt in distilled water. The preparation, although perfectly transparent when first formed, soon becomes turbid and deposits oxide of copper; this arises from the escape of ammonia, and may be prevented by the occasional addition of a small quantity of the volatile alkali. See Cuprum Ammoniatum. The Medicinal Dynameter will show the proportion of salt in any given quantity of the solution.

LIQUOR FERRI ALKALINI. L.

Solution of Alkaline Iron.

This preparation is nearly the same as Stahl’s Tinctura Martis Alkalina. Chemical Composition. It is by no means ascertained. Incompatible Substances. It is a most injudicious preparation, for it cannot be exhibited in any form without decomposition; water, especially if not distilled, and vegetable infusions and decoctions, produce dense precipitates; pure acids, alkalies, and spirit, also decompose it. I must confess my regret at the College having retained this preparation in their Pharmacopœia; the committee agreed to reject it, but their judgment was reversed by the votes of the Comitia Majora. Should any practitioner be unable to procure this preparation, I will give him an easy receipt for producing it, viz. Let him keep the Mistura Ferri composita in an open vessel, until it is entirely spoilt!

LIQUOR HYDRARGYRI OXY-MURIATIS. L.

This solution of corrosive sublimate is intended to facilitate the exhibition of minute doses of the salt; f℥j contains gr. ½; when long kept, or exposed to light, the oxy-muriate is decomposed, and calomel is precipitated; (see Hydrag: Oxymuriatis:) or, what is more dangerous, it is sometimes deposited in crystals, without decomposition; a small portion of muriatic acid, or muriate of ammonia in the solution, prevents this precipitation. Dose, fʒss to fʒij, in an infusion of linseed.

414LIQUOR PLUMBI SUB-ACETATIS. L.

Liquor Sub-Acetatis Lithargyri. D.

Aqua Lithargyri Acetati, P. L. 1767.

Solution of Sub-acetate of Lead: olim, Extract of Saturn.

This preparation was introduced by M. Goulard of Montpellier, hence it has been commonly known by the name of Goulard’s Extract. Qualities. It is of a greenish straw colour, and has an austere, sweetish taste; when kept it deposits a quantity of oxide, and becomes lighter coloured. Chemical Composition. It is a saturated solution of the sub-acetate of lead, consisting, according to Berzelius, of one proportional of acid, and three proportionals of oxide of lead; hence its name is correct. It is the only instance with which we are acquainted of a real sub-salt being soluble in water. Incompatible Substances. Alkalies and their carbonates precipitate a white sub-salt; alkaline sulphates and sulphurets; mucilage. Spring Water, from the salts which it contains, produces with it a very milky and turbid appearance; and even when distilled, in consequence of the carbonic acid diffused through it, it occasions precipitation. The Surgeon will remember that the Linimentum Saponis cannot be mixed with it, without mutual decomposition. See Sapo. Med. Uses. It is only used externally, in superficial and phlegmonic inflammations of the skin, and in herpetic affections. It has been a question whether Lead, in any form, should ever be applied to an open wound, or to an abraded surface;^[556] as a general rule, it should not certainly be applied to such as are recent, nor to those whose character indicates a diminished state of vitality in the parts, and exhibits a disposition to gangrene. The abuse of Saturnine lotions has been frequently descanted upon by foreign writers, and, among the evils which are supposed to be thus induced, impotence is mentioned as one of not unfrequent occurrence. See Institutioni di Medicina Forens: di Tortosa, vol. 1. p. 58. also Fritze Compend: sopra le Malat: Vener: p. 189. and Monteggia Annotat: sopra i Mali Venerei, p. 36. There is a paper in the third volume of the Medical Transactions, by Dr. Reynolds, in which the case of a gentleman is detailed, who brought on a temporary paralysis of the Sphincter Ani, by freely using Goulard’s lotion for the cure of the Piles. The value of Saturnine applications in common inflammation most probably arises from a partial paralysis of the nerves of the part, produced by the sedative agency of the lead.

LIQUOR PLUMBI SUB-ACETATIS DILUTUS. L.

As the former preparation is very rarely employed in its concentrated form, the College has directed its dilution, and added a portion of spirit, with a view to accelerate its evaporation, and thus to produce a refrigerating 415effect; but for such a purpose the quantity of spirit is far too small, and should therefore be increased by extemporaneous addition.

LIQUOR POTASSÆ. L. Aqua Potassæ. E.

Aqua Kali Caustica. D.

Aqua kali puri. P.L. 1787. Lixivium Saponarium, 1745.

Qualities. A limpid, dense, colourless solution; a pint should weigh ℥xvj; when rubbed between the fingers it feels soapy, in consequence of a partial solution of the cuticle. The solution, as usually prepared, contains small portions of muriate and sulphate of potass, silica and lime; but these incidental impurities do not invalidate its virtues; it ought not to effervesce with acids. Med. Uses. Antacid, diuretic, alterative, and lithonthryptic; and externally, when diluted, it acts as a stimulating lotion,^[557] and if concentrated, as a caustic; see Potassa Fusa. The operation of this and other alkaline remedies, have at different periods been celebrated as powerful lithonthriptics, and whilst experience has in some cases confirmed the value of the practice, it has in others proved no less decidedly its mischievous agency; these contradictory results are at length capable of explanation, for Chemistry has drawn aside the veil that has so long obscured the history, origin, and cure of calculous diseases, and has demonstrated that these extraneous bodies vary in composition, and are consequently very differently affected by the same chemical solvents; but this subject has already been so fully discussed in the first part of this work, under the chapter on “Antilithics and Lithonthryptics,” that it is unnecessary to dwell upon it in this place.

It has also been found highly useful in the cure of several species of cutaneous affections; as in Lepra, Psoriasis, &c. which diseases generally appear to have some connection with a morbid state of the digestive functions; see Form: 149. Dose of the solution of potass, ♏︎x to fʒss, in veal broth^[558] or table beer; this latter vehicle disguises its nauseous flavour completely. In many cases, the infusion of some bitter tonic will be the most eligible liquor in which it can be exhibited, especially where our object is to promote its absorption: the theory of such a combination has been already explained in the first part of this work, p. 153. Officinal Prep. Potassa fusa, L.E.D. Potassa cum calce, L.E.D. Liquor Sulphureti Kali, D. Antimonii Sulphuretum Præcipitatum, L.E.

416LIQUOR POTASSÆ SUB-CARBONATIS. L.

Aqua Sub-carbonatis Kali. D.

Aqua Kali præparati, P.L. 1787.

Lixivium Tartari. 1745.

Oleum Tartari per deliquium, P.L. 1720.

Qualities. It is a clear, colourless, and inodorous solution; Spec. grav. 1·446. Dose, ♏︎x to fʒj. See Potassæ Sub-carbonas, and Form: 39, 41. The proportion of the salt contained in any quantity of the solution may be learnt by referring to the Dynameter.

LIRIODENDRON TULIPIFERA.

American Tulip bearing poplar.

Cortex.

[This is a native tree of America, and one of the most magnificent to be found in our forests—distinguished no less by its great altitude than by its beautiful foliage. It grows in almost every part of the United States. The part used in medicine is the Bark. This has a rough, fibrous appearance and is of a whitish colour. Its taste is bitter, astringent, and somewhat acrid and aromatic. By analysis, it yields gum, resin, muriatic acid, iron, mucus, &c. In its action on the system, it is decidedly tonic, exhibiting at the same time, to a certain extent, stimulant properties. If given in considerable quantities it acts also on the skin and kidneys. It has been used with advantage and success in intermittent fever, chronic rheumatism, gout, hysteria, and in debilitated states of the stomach. It may be given in substance, which is the most efficacious form of using it, in doses of from ʒss to ʒij.]

LOBELIA INFLATA.

Indian Tobacco. Herba.

[This is a plant very common in the United States. It has an acrid taste, very similar to that of green tobacco. By analysis it is found to contain an acrid principle, caoutchouc, and extractive. It is soluble both in water and alcohol. In its medicinal effects, the lobelia is analogous to common tobacco, and varies very much according to the dose in which it is given. It may thus be made to act either as an emetic, antispasmodic, expectorant, or diaphoretic. The diseases in which it has been found useful are asthma, croup, hooping cough, and catarrh. The tincture is the best preparation, and is prepared by digesting, for ten days, ℥ij of the plant in a pint of diluted alcohol. The dose is from ʒj to ʒiv—of the powder, the dose to prove emetic is from 10 to 20 grs.]

417MAGNESIA. L. Magnesia Usta. D.

Calcined Magnesia.

Qualities. Form, a white, very light, soft powder; Specific gravity, 2·3; it turns to green the more delicate vegetable blues. Solubility. Although it requires 2000 times its weight of water to hold it in solution, yet it has the property of considerably increasing the solubility of camphor, opium, and resins in the same fluid; it is soluble in solutions of the alkaline carbonates, but not in those of caustic alkalies. Chemical Composition. It is an oxide of a peculiar metal. Medicinal Uses. Antacid, and when acidity prevails, purgative; it is preferable to the carbonate whenever the bowels are distended with flatus, (Form: 150): in other respects, its virtues are the same. See Magnes. Carb. The Medicinal Dynameter will shew the equivalent doses of the pure earth and its carbonate; it will be seen for instance that 12 grains of the former will be as efficient, as an antacid, as 25 grains of the latter. Incidental Impurities. It ought not to effervesce with acids, and if magnesia and muriatic acid be placed at one time in separate cups, in a scale of a balance, no diminution of weight should take place on mixing them. Lime is detected by its solution in dilute sulphuric acid affording a precipitate with oxalate of ammonia; the sulphuret of lime betrays itself by yielding, when moistened, the smell of sulphuretted hydrogen.^[559]

MAGNESIÆ SUB-CARBONAS. L.

Carbonas Magnesiæ. E. Magnesia. D.

Olim, Magnesia Alba.

Carbonate of Magnesia, vulgo, Common Magnesia.

This preparation was formerly considered by Mr. Phillips to be a mixture of carbonate and sub-carbonate of magnesia, an opinion which he has lately retracted; it is, says he, evidently a carbonate, i. e. magnesia combined with one proportion of carbonic acid, or forty-eight of carbonic acid to forty-three of magnesia. Dr. Thompson entertains a different opinion, he observes that it seems to be a mechanical mixture of carbonate of magnesia, caustic magnesia, and perhaps of hydrated magnesia; he found too great a diversity in its composition to permit the conclusion that it was a definite chemical compound; in a specimen purchased at Glasgow, he also found six per cent. of sulphate of lime. I take this opportunity of stating that in some specimens which I have examined, I have also detected portions of gypsum; and from the experiments of Dr. Percival, it appears that if hard water be employed for its preparation it will be less light, and will contain a portion of lime. Magnesia will be also liable to contain 418traces of silicious earth, derived from the alkali used in producing it. Incompatible Substances. Acids, and acidulous salts; alkalies and neutral salts; alum; cream of tartar; nitrate of silver; acetate of mercury; oxy-muriate of mercury; acetate of lead; sulphates of zinc, copper, and iron. Medicinal Uses. Antacid, and purgative. In cases of lithic calculi, carbonate of magnesia, in doses of ℈j to ʒj, has been proposed by Mr. Hatchett, as a valuable substitute for alkaline remedies. Its insolubility must render its absorption equivocal; its beneficial operation must therefore principally depend upon its neutralizing any excess of acid in the primæ viæ, and in this way there can be no doubt of its lithonthryptic agency; “but,” says Dr. Marcet, “such is the tendency which the public has to over-rate the utility of a new practice, or to take a mistaken view of its proper application, that there is every reason to believe that the use of magnesia has of late years become a frequent source of evil in calculous complaints.” See page 124. Officinal Prep. Hydrarg. cum Magnesia. D. Magnesia. L.E.D. Adulterations. Chalk may be detected by adding dilute sulphuric acid to a suspected portion, when, should any be present, the solution will be loaded with a white and insoluble precipitate; gypsum, by boiling a sample in distilled water, and assaying the solution by a barytic and oxalic test.^[560]

MAGNESIÆ SULPHAS. L. Sulphas Magnesiæ. E.D.

Magnesia Vitriolata. Sal catharticum amarum.

Bitter purging Salt. Epsom Salt.

Qualities. Form, small needle-like crystals. Taste, bitter and nauseous; when pure, it effloresces. Chemical Composition. In its crystallized state, it may be considered as composed of 1 proportional of dry sulphate (Magnesia 18·5, and sulphuric acid 37·5) and 7 proportionals of water. Solubility. f℥j of water dissolves ℥j, and the solution measures fʒxj¼; it is insoluble in alcohol. Incompatible Substances. Muriates of ammonia, baryta, and lime; nitrate of silver; sub-acetate, and acetate of lead. The fixed alkalies and their carbonates, precipitate from it magnesia and its carbonate. Phosphate of soda occasions no immediate precipitate, unless ammonia be present, in which case the triple ammoniaco-magnesian phosphate will be produced. The addition of ammonia, which in the form of Spiritus ammoniæ aromat. is not unfrequently prescribed in conjunction with a solution of this sulphate, forms also a triple salt, and a portion of magnesia is precipitated: whenever therefore this ammoniacal stimulant is 419ordered with a purgative salt, the scientific physician will prefer a solution of the sulphate of soda. Forms of Exhibition. Dissolved in the Infusum Rosæ, or in a suitable quantity of beef tea, gruel, or any aqueous vehicle, its cathartic powers are increased by dilution, as well as by the addition of a little common salt; magnesia renders the taste of its solution less nauseous; and tartarized antimony quickens its operation. Dose, ℥ss to ℥ij, taken either at once, or in divided doses. Form. 37, 69, 72, 76. Officinal Prep. Enema Catharticum. Enema Fœtid. D. Adulterations. Sulphate of Soda is often substituted for this salt, which it may be made to resemble by stirring it briskly at the moment when it is about to crystallize; the fraud may be detected by a precipitation not ensuing on adding carbonate of potass; if only a part of the salt be sulphate of soda, the degree of sophistication can be learnt by the quantity of the precipitate formed; 100 parts of sulphate of magnesia, if pure, will yield between 30 and 40 of the dry carbonate. Epsom salt, as it commonly occurs, contains muriate of magnesia, which disposes it to deliquesce, but lately this salt has appeared in the market in a state of great purity and beauty; the mode of purification is founded upon the well known chemical law, that a saturated solution of one salt is still capable of dissolving another; in the present instance, therefore, the impure crystals are washed in a saturated solution of the same sulphate, which, although unable to act upon its kindred salt, can dissolve with facility the muriate, and any other saline contamination. I confess, however, that I am induced to regard this process as rather chemically ingenious than as medicinally useful, for the usual saline impurities of Epsom salt are not only harmless, but capable of increasing its purgative powers; the double refined sulphate is certainly less efficient as a cathartic. The presence of the muriate may be at once detected by dropping upon the suspected sample some sulphuric acid, by which the disengagement of muriatic acid vapour will be produced. Since the publication of the fourth edition of the present work, I have received samples of the sulphate of Magnesia, prepared by Mr. West of Lymington, and I can confidently recommend the article to the profession; he contrives to obtain them in large and beautiful crystals, which cannot be so easily mistaken for those of oxalic acid, a circumstance of no small importance to the drug vender; the form of these crystals is that of a square prism, having its edges replaced, and commonly terminated by a pyramid of four planes; the only cleavage is parallel to one of the diagonals of the prism. The numerous accidents which so frequently occur from mistaking Oxalic acid for Epsom Salts have given rise to many suggestions for obtaining an easy and popular test which may at once distinguish these bodies; it is evident that no test can be so simple as that afforded by the taste; but if such accidents are in future to be prevented, it must be done by imparting to the acid some external character by which it may be at once recognised; if a test were even discovered a hundred times more sensible than any which we possess, what would it avail?

420MANNA.^[561] L.E.D.

(Fraxinus Ornus. Succus Concretus.)

Manna.

Qualities. Form, flakes of a granular texture; Colour, whitish, or pale yellow; Odour, slight but peculiar; Taste, nauseous sweet, with some degree of bitterness. Chemical Composition. This concrete vegetable juice, besides sugar, appears to contain mucilage and extractive, to which its taste and other peculiar properties are owing. Solubility. It is entirely soluble in water and alcohol. Med. Uses. It is now merely regarded as a laxative for children, or for weak persons. It generally requires some laxative adjunct, as castor oil, with which it may be combined by the medium of mucilage. Dose, for children, from ʒj to ʒiij, in warm milk. Officinal Prep. Confectio Cassiæ. L.E.D. Enema Cathart. D. Enema Fœtid. D. Syrup. Sennæ. D. Adulterations. There are several varieties in the market, the best of which is flake manna, manna canulata, in a stalactitic form. An article, entirely factitious, consisting of honey or sugar, mixed with scammony, is sometimes sold for genuine manna, but its colour, weight, transparency, and taste, must instantly lead to its detection.

MASTICHE. L.

(Pistachia Lentiscus. Resina.)

Mastich.

The use of this resinous substance is to fill the cavities of carious teeth; a solution of it in oil of turpentine is sold as an odontalgic. The Turkish and Armenian women use it as a masticatory for cleaning the teeth, emulging the salivary glands, and imparting an agreeable odour to the breath. It forms a constituent of the Dinner Pills. See Aloes. Sonnini tells us that, in Egypt, the smoke of Mastich is supposed to kill any sick person that inhales it.

MEL. L.E.D. Honey.

This well known substance appears to be merely collected from the flowers, and not elaborated by the internal economy of the insect; when properly diluted it undergoes vinous fermentation, the product of which is the beverage well known by the name of Mead. The English honey is more waxy than that from the south of Europe. Virgin honey is that wrought by young bees which have never swarmed, and permitted to run from the comb without heat or pressure. Chemical Composition. Sugar, mucilage, wax, an acid, and occasionally some essential oil. Clarified Honey, (Mel Despumatum. L.D.) has not the agreeable smell of crude 421honey; it does not however ferment so readily, nor is it so apt to gripe. Uses. It is principally employed for forming several officinal preparations, i. e. Mellita, viz. Mel Boracis. L. Mel Ros. L.D. Oxymel. L.D. Oxymel Colchici. E. Oxymel Scillæ. L.D.^[562] Sir John Pringle considered it as useful in nephritic disorders; it possesses also a laxative property, which renders it on many occasions preferable to Syrup. Adulterations. Flour may be detected by diffusing the honey in tepid water, by which it will be separated, and, by subsequent boiling, converted into a thick paste.

MELIA AZEDARACH.

Pride of China. Cortex radicis.

[This plant is a native of the East Indies, from whence it was introduced into Europe and North America. The part used in medicine is the bark of the root. It is a powerful anthelmintic, and affects the system in a way very similar to the Spigelia Marylandica, producing not unfrequently confusion of the head, stupor, trembling of the hands, &c. This is particularly the case if it be used in the months of March and April, when the sap rises in the tree. It is chiefly against the round worm that the Melia has been found successful, though in some cases it has proved effectual also against the Tænia. It is generally given in the form of decoction: to prepare this, ℥iij or ℥iv of the bark of the fresh root are put into a quart of water and boiled down to a pint, of which ℥ss to ℥j may be given every two or three hours till it operates. Administered in this way, it frequently causes both purging and vomiting.]

MENTHA PIPERITA. L.E.D.

Mentha Piperitis. D. Peppermint.^[563]

All the qualities of this plant depend upon an essential oil and camphor; it readily and strongly impregnates either water or spirit, by infusion; its infusion, and the water distilled from the plant, are carminative and antispasmodic; they also serve as vehicles for other medicines, to correct their operation, or to disguise their flavour. Officinal Preparations. Aq. Menth. Piperit. L.E.D. Spir. Menth. Pip. L.D. Ol. Menth. Pip. L.D. If this plant be cut in wet weather, it turns black, and is worthless.

MENTHA VIRIDIS. L. Mentha Sativa. D.

Spearmint.

Cold water extracts the more agreeable and active parts of mint in a few hours; a longer maceration extracts the grosser and less agreeable portions; hot water more quickly extracts its virtues, but if it be boiling it dissipates the aroma. Officinal Preparations. Aq. Menth. virid. 422L.D. Infus. Menth. comp. D. Ol. Menth. virid. L. D. Spir. Menth. virid. L.

MEZEREI CORTEX. L.E.D.

(Daphne Mezereum. Radicis Cortex.)

Mezereon.

The inner bark of this plant, when fresh, is corrosive and even vesicatory; the fruit is equally so, but neither have any smell; its virulence is counteracted by camphor. It contains, besides extractive matter, an acrid resinous substance, which, according to Plaff, bears a strong resemblance to the active principle of Cantharides. It is now seldom used except as an antivenereal remedy, or in cases of chronic cutaneous disease. Forms of Exhibition. In a decoction, made by boiling ℥ss of the bark, with an equal quantity of Liquorice root, in oiij of water down to oij; of which f℥ss may be given twice a day. From its pungency it is one of the substances used by fraudulent brewers to communicate a strong flavour to their beer. Where a discharge from issues cannot be kept up by the common means, it is said that the introduction of a little of this bark, instead of the pea, will in a few hours produce the desired effect. Officinal Preparations. Decoct. Sarsaparill. comp. L. Decoct. Daphnes. Mezerei. E. The Daphne Laureola is very generally sold for Mezereon.

MISTURÆ. L.E.D. Mixtures.

The principles upon which this form of preparation is to be constructed, are fully detailed in the first part of this work, page 199.

Officinal Mixtures.

Mistura Ammoniaci. L. This mixture is expectorant, and may be exhibited with tincture of squills, &c. (Form. 115, 136.) It is slightly curdled by vinegar, oxymel, æther, and oxy-muriate of mercury.

Mistura Amygdalarum. L. Emulsio Amygdali communis. E. Lac Amygdalæ. D. It is a useful demulcent and diluent, and forms an elegant vehicle for more active medicines. Incompatibles—Acids, Oxymel, Syrup of Squill, Spirit, and Tinctures, unless added in very small quantities, decompose this mixture; tartaric acid, super-tartrate of potass, and oxy-muriate of mercury, also disturb it. Form. 137.

Mistura Assafœtidæ. L. A nauseous preparation; and where its use is indicated, it will be more judicious to prescribe it as an extemporaneous mixture. See Assafœtida.

Mistura Camphoræ. L. This solution of camphor forms an elegant vehicle for more active stimulants. The camphor is separated from the water by a solution of pure potass, by sulphate of magnesia, and by several saline bodies. See Form. 7, 24, 25, 32, 47, 72, 116, 117, 123.

Mistura Cornu Usti. L. Decoctum Cornu Cervini. D. This is nothing more than a simple diffusion of phosphate of lime in a thin mucilage—Cui bono? It was retained in the Pharmacopœia in deference to the opinion of some experienced practitioners.

423Mistura Cretæ. L.D. A common and useful remedy in diarrhœa, and may be combined with opium, catechu, or any other astringent. Form. 52. It is of course incompatible with acids, and acidulous salts.

Mistura Ferri Composita. L. This is nearly the same as the celebrated anti-hectic mixture of Dr. Griffith; to the result of the decompositions which take place from the mixture of its ingredients, it is wholly indebted for its medicinal energies; thus, a proto-carbonate of iron is formed, i. e. the iron combined with carbonic acid is at its minimum of oxidation, which renders it more active than the common carbonate, and probably less stimulant than the sulphate; this product, by means of the saponaceous compound formed by the union of the myrrh with the excess of alkali, is partly diffused and suspended in the mixture, and partly dissolved, whilst at the same time a sulphate of potass is formed, which serves to correct the astringent influence which iron is apt to exert upon the bowels. The iron in this preparation is disposed to combine with an additional proportion of oxygen, hence its ingredients should be quickly mixed together, and it ought to be considered as an extemporaneous preparation, and be preserved in a closely-stopt vessel. Its change of colour will generally indicate its loss of efficacy. This preparation must be regarded as permanently serviceable in Chlorosis, and the numerous sympathetic affections connected with it. In the painful swellings which infest the breasts of chlorotic young women, I have found it almost a specific. Dose, f℥j-f℥ij. The proportion of Proto-carbonate of iron, contained in any given quantity of this mixture, may be found by referring to the Medicinal Dynameter; for instance, bring the preparation to 12, and we shall perceive that this number of fluid-drachms contain 1 grain of Protoxide, or rather more than gr. iss of Proto-carbonate of iron; and we shall, at the same time, perceive that to give an equivalent quantity in the form of Pil. Ferri comp. we must prescribe ℈j. See Form. 96.

Mistura Moschi. This is an eligible form for the administration of Musk. Dose, f℥j-f℥ij, to which may be added extemporaneously, ammonia, æther, and other diffusible stimulants.

The Dose of the above mixtures is f℥j-to f℥ij twice or thrice a day.

MOSCHUS. L.E.D. Musk.

Qualities. Form, grains concreted together, dry, yet slightly unctuous. Colour, deep brown with a shade of red; Odour, aromatic, peculiar, diffusive, and durable; and it has the curious property, when added in a minute quantity, to augment the odour of other perfumes without imparting its own; this renders it a valuable article in perfumery, on which account it is a usual ingredient in lavender water. Taste, bitterish and heavy. Chemical Composition. Resin combined with volatile oil, and a mucilaginous extractive matter, with small portions of albumen, gelatine, muriate of ammonia, and phosphate of soda. Solubility. Boiling water dissolves it perfectly; rectified spirit takes up most of its active parts, although the odour is only discovered upon dilution; sulphuric æther is its most complete menstruum. Incompatible Substances. The solutions are decomposed by Oxy-muriate of Mercury; Sulphate of Iron; Nitrate of Silver; and the Infusion of Yellow Bark. Med. Uses. Stimulant and antispasmodic. As early as the time of Meade it was employed in typhus fever; Pringle administered it in gout of the stomach, a practice which received the concurrence of Cullen; conjoined with ammonia 424it has been celebrated for its powers in arresting the progress of gangrene, and of imparting fresh excitement to the nervous system. It has been also administered with success in epilepsy, hooping cough, and other spasmodic affections. Forms of Exhibition. The best form is that of bolus, combined with ammonia or camphor, or some other similar remedy, (Form. 21); it may be also administered in a mixture, for which purpose it requires five times its weight of mucilage, consequently the London College has not directed a sufficient quantity to retain the musk in suspension: by previously triturating it with sugar, its minute division is much facilitated. Dose, grs. x to xxx. See Form. 22, 30. Officinal Prep. Mist. Mosch. L. Tinct. Mosch. D. Adulterations. The bag containing the musk should have no appearance of having been opened: the presence of dried blood may be suspected, by its emitting, as it inflames, a fetid smoke; Asphaltum is discovered by its melting and running before it inflames: the artificial bags are known from the deficiency of the membrane which lines the real musk bags. To increase the weight of the musk, fine particles of lead are frequently added; this is easily detected, for by rubbing it with water the metallic particles will subside.

Moschus Factitius. Artificial Musk, strongly resembling the real, may be formed by digesting f℥ss of Nitric Acid, for ten days, upon ℥j of fetid animal oil, obtained by distillation; to this is to be next gradually added oj of rectified spirit, and the whole is then to be left to digest for one month: or—

2. Drop fʒiiiss of nitric acid upon fʒj of rectified oil of amber; after standing twenty-four hours, a black, resinous pellicle, exhaling the odour of musk, will be formed.

MUCILAGO ACACIÆ. L.E.

Mucilago Gummi Arabici. D.

This preparation consists of one part of gum and two of water; in preparing it, the dispenser is particularly recommended to pulverize the gum, and never to employ that which is purchased in the state of powder, as it is always impure and incapable of forming a pellucid and elegant solution.^[564] Incompatible Substances. Neither the strong acids nor alcohol, when considerably diluted, occasion any disturbance in it; but sulphuric æther and its compound spirit, the tincture of muriated iron, and sub-acetate of lead, produce very dense precipitates: the acetate of lead only occasions decomposition, when an alkaline salt is present in the formula; the volatile alkali curdles the mucilage, and hard calcareous waters render the mixture difficult and often impracticable. In the pharmaceutical application of this mucilage, it should be remembered that it contains in its composition an astringent principle, which is perhaps of but trifling consequence except in the exhibition of some very few active metallic salts, which are certainly decomposed by it (e. g. grs. x of nitrate of mercury are decomposed by ʒij of gum arabic.^[565]) It contains also lime in combination with 425some vegetable acid. Uses. Diluted with four times its bulk of water, this mucilage forms a demulcent mixture of appropriate tenacity, which affords a convenient vehicle for several efficient remedies; the pharmaceutical use of this mucilage depends upon the fact of its rendering expressed and essential oils, balsams, resins, gum-resins, resinous tinctures, and fatty bodies, miscible with water, but if a syrup be added, the union will be more perfect; the proportions necessary for this purpose vary according to the nature of the substances; thus, oils will require about three-fourths their weight, Balsams and Spermaceti an equal part, Resins a double quantity, and Musk five times its weight; the following Formulæ illustrate this property, 9, 19, 22, 135.

MUCILAGO AMYLI. L.E.D.

Mucilage of Starch.

This is a strong, insipid, inodorous mucilage, which is principally employed as a vehicle for exhibiting Opium in the form of Enema, see Amylum.

MUCILAGO ASTRAGALI TRAGACANTHÆ. E.D.

Tragacanth Mucilage.

Tragacanth is, strictly speaking, not soluble in water, but imbibes a large portion of it and swells into a considerable bulk, forming a soft but not a liquid mucilage; on the farther addition of water, a fluid solution may be obtained by agitation, and the liquor is turbid; but on standing, the mucilage subsides, the limpid water on the surface retaining a little of the gum;^[566] it differs from all gums in giving a thick consistence to a larger quantity of water, its power in this respect being to that of gum arabic as twenty to one; one part converts twenty of hot water into a stiff mucilage. Tragacanth is not increased, but actually diminished in solubility by the addition of any other gum, it accordingly separates from water with much greater facility when gum arabic is present. This preparation, according to the Edinburgh college, consists of one part of gum and eight of water; the resulting mucilage is stiff, and is principally employed for making troches. The Dublin preparation contains four times that quantity of water.

MYRISTICÆ NUCLEI. L.E.

Nux Moschata. D. Nutmeg.

All the properties of this well-known substance depend upon an essential oil, filling the dark coloured veins which run through its substance, the other components are starch, gum, wax, and a fixed oil. The oil obtained by expression is improperly called oil of mace, for it would appear 426to be a triple compound of fixed oil, volatile oil, and wax, and which, although limpid when first drawn, soon acquires on cooling the consistence of spermaceti. Mace is the involucrum of the nut. Med. Uses. Stimulant, and in large doses, as from ʒij to ʒiij, narcotic, frequently producing delirium. See Cullen Mat. Med. ii. 201. Officinal Prep: Spir: Myristicæ. L.E.D. Frauds. Nutmegs are frequently despoiled of their essential oil, by being punctured and submitted to the operation of decoction, the orifices being subsequently closed by powdered Sassafras; the imposition is detected by the comparative lightness of the nutmeg, and by its extreme fragility; the holes may also be discovered by carefully examining the surface of the nut, after having steeped it in hot water.

MYRRHA. L.E.D.

(Arboris nondum descriptæ, Gummi-resina.)

Myrrh.

Qualities. Form, irregularly shaped pieces, translucent, of a reddish yellow colour; Odour, peculiar and fragrant; Taste, bitter and aromatic. Chemical Composition. Resin, gum, essential oil, and some extractive. Solubility. When triturated with soft, or distilled water, nearly the whole appears to be dissolved, forming an opaque, yellowish solution, but by rest the greater part is deposited, and not more than one-third is actually dissolved; its solubility, however, in water may be increased by trituration with camphor or an alkali; rectified spirit dissolves it, and the resulting tincture, when diluted, becomes turbid, although no precipitate occurs. Med. Uses. Stimulant, as in Form. 103. Expectorant, 132, 133, 138. Emmenagogue, 95, 98, 99. It is also tonic, and agrees with some constitutions better than any of the bitters. Forms of Exhibition. No form is so eligible as that of substance. Dose, grs. x to ʒj. The alkalies, in their crystalline state, when triturated with myrrh, reduce it to the form of a tenacious fluid. Officinal Preparations. Tinct. Myrrh. L.E.D. Tinct. Aloes et Myrrh. E. Tinct. Aloës Ætherea. E. Mist. Ferri comp. L. (G L) Pil. Aloes cum Myrrha. L.E.D. Pil. Ferri cum Myrrha. L. Pil. Galb. comp. L.D. (B) Pil. Assafœtid. comp. E. (B) Pil. Rhei, comp. E. (G) Adulterations. It is subject to a variety of frauds, being frequently mixed with adventitious gums, which are to be detected by their foreign odour, their white or dark colour, and by their opacity.

NUX VOMICA. (Strychnus Nux Vomica.)

Nux Vomica.

This seed has not at present a place in the British pharmacopœiæ; it presents however several points of interest to the physiologist, the physician, and the chemist. Its virulent action upon animals has been long known; and it has been administered in combination with gentian in intermittents.^[567] (Ludovic. Phar. p. 113,) and as a narcotic in mania; it also 427constituted an ingredient in the famous Electuarium de ovo, (Ph. Angl. p. 263.) Nux vomica has been said to produce benefit in the plague; the German writers have strongly commended it in mania, epilepsy, and hydrophobia; as well as in chronic rheumatism, gout, scrophula, lues venera, and cutaneous eruptions; in Sweden it is stated to have displayed very beneficial effects in Dysentery. Dr. Fourquier has lately introduced its use in the Hopital de la Charité, in cases of partial paralysis, and it is said, with very great success.^[568] The value of the practice has been since confirmed by the experiments of Dumeril, Majendie, Hebreard, Husson, and Asselin. The dose is four or five grains of the powder in pills, during the day. The French codex contains two alcoholic extracts of this substance; the one prepared with a strong spirit (22, 32, Beaumé, i. e. from sp. gr. ·915 to ·856,) is much more active and powerful than that made with a weak spirit. (12, 22, Beaumé, i. e. from sp. gr. ·985 to ·915.)

M. M. Pelletier and Caventou have discovered in this substance, a peculiar proximate principle, to which its virulence is owing; it was named Vauqueline, in honour of the celebrated French philosopher, but in deference to the opinion of the French Academy of Sciences, the discoverers have substituted the name Strychnia, because “a name dearly loved, ought not to be applied to a noxious principle!”^[569] (Annales de Chimie, vol. 8 to 10.) Strychnia is highly alkaline, and crystallizes in very small four-sided prisms, terminated by four-sided pyramids; its taste is insupportably bitter, leaving a slight metallic flavour, and is so powerful as even to be perceptible when a grain is dissolved in eighty pounds of water;^[570] it has no smell; is not changed by exposure to the air, nor is it either fusible or volatile, for when submitted to the action of heat, it only fuses at the moment of its decomposition which takes place at a temperature inferior to that which destroys most vegetable substances; it is so extremely active and violent, that in doses of half a grain it occasions serious effects, and in larger ones convulsions and death; it is perhaps the most powerful,^[571] and next to hydro-cyanic acid, the most rapid of poisons; notwithstanding its strong taste, it is very sparingly soluble in water, requiring 6667 parts of that fluid for its solution at 50, and 2500 at 212°. It is very soluble in alcohol, but unlike most of the other vegetable alkalies, is nearly insoluble in æther; with acids it forms neutral and crystallizable salts; these salts as well as their base, have the singular property of becoming bloodred by the action of concentrated nitric acid. The alcoholic solution of Strychnia has the property of precipitating the greater number of metallic oxides from their acid solutions. It is precipitated by alkalies and alkaline earths. Strychnia exists in native combination in the Strychnus with an acid which has some analogy with the malic, and which Pelletier and Caventou propose to call the Igasuric acid, from the Malay name for the 428bean of St. Ignatius,^[572] (Strychnus Ignatius,) in which its properties were first examined. In conformity with such views, the active principle of the tribe of Strychni is an Igasurate of Strychnia;—a fact which suggests the existence of a most singular and striking analogy between the chemical constitution of these narcotico-acrid bodies^[573] and that of opium. The recent experiments of Pelletier have shewn, moreover, that besides Strychnia, the Nux Vomica contains Brucia, an alkaline body which had been previously discovered in spurious Angustura. Its properties are similar to those of Strychnia, but it is less active. Being much more soluble in alcohol than Strychnia, if care be taken to crystallize the latter several times in alcohol, it will be separated, the Brucia remaining in the mother waters. Strychnia has been given in doses of one-twelfth of a grain, but it is a most dangerous remedy, and is liable to occasion tetanic convulsions.^[574] It has been said, however, to prove serviceable in cases of Epilepsy that had resisted every other method of cure. Dr. Fleming informs us that the Hindoos of upper India are in the habit of adding Nux Vomica in the process of distilling Arrack, for the purpose of rendering the spirit more intoxicating. The London Porter brewers have been accused of the same pernicious practice.

429OLEA DESTILLATA. L. Ol. Volatilia. E.

Ol. Essentialia. D.

Distilled, Volatile, or Essential Oils.

The British pharmacopœiæ direct them to be obtained by distillation only; the French codex orders several of them to be prepared by expression. Qualities. Form, liquid, sometimes viscid; specific grav. various; oil of turpentine, which is the lightest, being only 0·792, whilst the oil of cloves, cinnamon, and allspice, exceed 1·030, and that of sassafras, which is the heaviest, amounts to 1·094; these latter oils hold resin in solution, and of course sink in water. Odour, penetrating and fragrant; Taste, acrid; they are volatilized at a temperature somewhat below that of boiling water; they are very inflammable. Solubility. Very soluble in alcohol, forming what are termed in perfumery Essences; in water they are very sparingly soluble; the solutions are known in pharmacy under the title of distilled waters; they are also dissolved by æther, and the fixed oils; when digested with ammonia, some of the less odorous acquire a considerable degree of fragrance, whilst on the contrary, fixed alkalies universally impair their odour; they are rapidly decomposed by nitric and sulphuric acids, and their action is sometimes attended with instant inflammation. Volatile oils, from continued exposure to the air, absorb oxygen, and become resinous, by which they lose their volatility, fragrance, and pungency, hence they should be preserved in small opaque phials, completely full and well stopped. Med. Uses. They act as powerful stimulants and aromatics; they remove nausea and flatulence, correct the griping of certain purgatives, and cover the offensive taste of various remedies. See Aquæ destillatæ. They, moreover, have the property of defending certain animal and vegetable preparations from mouldiness. This curious fact has been already noticed, see page 177. The following is a list of the species admitted into our British pharmacopœiæ; those designated in italics are principally for internal use. Olea Anisi, Anthemidis, Carui, Juniperi. Lavandulæ, Menthæ Piperitæ, Menthæ viridis, Origani, Pimentæ, Pulegii, Rosmarini, L. Olea Volatilia, Juniperi communis, Juniperi Sabinæ, Lavandulæ Spicæ, Lauri Sassafras, Menthæ Piperitæ, Myrtæ Pimentæ, Pimpinellæ Anisi, Rorismarini Officinalis. E. Olea Juniperi, Pimento, Corticis et Ligni Sassafras, e Seminibus Anisi, Carui, Fœniculi dulcis, Florum Lavendulæ, Foliorum Sabinæ, Herbæ florescentis Menthæ Sativæ, Origani, Pulegii, Rorismarini, Rutæ, D. Adulterations. Fixed Oils may be detected by moistening writing paper with the suspected article and holding it before the fire: if the oil be entirely essential, no stain of grease will remain; as castor oil is more soluble in spirit than the others, it is the one generally selected for this fraudulent purpose, and the addition of alcohol restores the sophisticated oil to its proper degree of consistency. Alcohol is discovered by adding water, which, if it be present, occasions a milkiness, and at the same time, an increase of temperature; a decrease of bulk also takes place, which may easily be ascertained by measuring the oil and water separately, and then transferring them, in a state of mixture, into a tube of small diameter. Cheaper oils, as that of turpentine, are recognised by their peculiar odour, which may be developed by rubbing a drop upon the hand and holding it to the fire, or, by the 430dense black smoke with which they burn. The oil of aniseed, as it crystallizes at 50°, is frequently sophisticated with wax, spermaceti, or camphor; the fraud is detected by warming the oil, when the crystals, if genuine, will dissolve.^[575] In some cases the refractive power of the oil affords a test of its purity. See my work on Chemistry in its relations to Medicine, § 318.

OLEA EXPRESSA. L.D.

Olea Fixa, sive Expressa. E.

Expressed or Fixed Oils.

These are obtained from animal matter by fusion, and from vegetable by expression, or decoction with water. Qualities. Odour, none; Taste, mild; they boil at 600°, but undergo decomposition, becoming acrid and empyreumatic; the oil, in this state, was formerly used in medicine under the name of philosopher’s oil.^[576] By exposure to air they absorb oxygen and become rancid; they congeal at a temperature of 32°, and some even above that. When the oil is expressed by heating the plates of the press, or by previously roasting the seeds, it is more disposed to become rancid; cold drawn oils are on this account to be preferred for the purposes of pharmacy. Solubility. They are insoluble in water, and, except castor oil, nearly so in alcohol and æther; with caustic alkalies they combine and form soaps; when aided by heat they readily unite with oxide of lead, forming the solid compound well known by the term plaister. They unite also very readily with each other, and with volatile oils. Solvent Powers. They dissolve sulphur, and form a kind of balsam with it; they also possess the power of extracting and dissolving the narcotic and acrid principles of several vegetable and animal substances, in consequence of which, the French pharmacopœia directs a series of preparations under the term “Olea Medicata;” thus there are olea Cicutæ, Hyoscyami, Solani, Stramonii, Nicotianæ;^[577] which are made by digesting with a gentle heat, one part of the subject in two parts of olive oil.^[578]

OLEUM AMYGDALARUM. L.E.D.

Oil of Almonds.

This fixed oil, whether procured from the sweet or bitter almond, has the same properties, for the bitter principle resides exclusively in combination 431with a peculiar volatile oil attached to the mucilage;^[579] that from the latter keeps longer without rancidity. It is sometimes made from old Jordan almonds, by heat, in which case it very soon grows fetid. Nut oil, Oleum nucum Coryli, has been proposed as a substitute for that of almonds; in China it is drunk with tea, instead of cream. Medical Uses. For forming emulsions, in coughs, and other pulmonary complaints. Forms of Exhibition. It may be formed into an emulsion by the intermedium of mucilage, the yelk of an egg, or by that of an alkali.

1. By Mucilage. This is in general a more convenient medium than the yelk of an egg; one part of gum, made into mucilage, will be sufficient for the diffusion of four parts of oil, (see Mucilago Acaciæ) the oil and mucilage must be carefully triturated together, and the water then gradually added; the emulsion thus formed is permanent, and the addition of a moderate quantity of acid, spirit, or tincture, will not produce decomposition. See Form. 73.

2. By Alkalies. This oil, by uniting with alkalies and water, forms an elegant and grateful mixture, for which purpose the following proportions are to be observed, every fʒj of oil requires ♏︎viij of liquor potassæ, and f℥iss of distilled water. Incompatible Substances. Acids; oxymel; syrups of poppies and squills; tartrate and super-tartrate of potass; super-sulphate of potass; oxy-muriate of mercury; resins; hard water. See Form. 166, 167.

OLEUM AMYGDALÆ AMARÆ VOLATILE.

Qualities. Colour, pale yellow; Odour, fragrant and pungent, having the characteristic smell of prussic acid. Taste, pungent, bitter, and peculiar. Solubility. Like other essential oils, its sensible properties and medicinal effects are imparted to water; in alcohol it is very soluble.^[580] Chemical Composition. A peculiar oil, combined with hydro-cyanic acid. M. Vogel of Munich has lately succeeded in separating these constituents, by agitating the whole in a concentrated solution of potass, and distilling to dryness; the oil volatilized together with water, while the residuum in the retort was found to contain Cyanide of Potassium. The volatile oil, thus purified, is without odour, and heavier than water. Its taste is extremely acrid and burning; by contact with air it crystallizes rapidly; it dissolves easily in alcohol and æther, but only in a very small proportion in water. The flame of its combustion is very brilliant, and accompanied with much smoke. In order to discover whether this oil, when freed from its hydro-cyanic acid, is still poisonous, M. Vogel put a drop of it on the tongue of a sparrow; when it died, after violent convulsions, in a few seconds; he also poisoned a dog, two months old, with four drops of it; whence he concludes that the volatile oil, divested of its hydro-cyanic acid, is still a poison, although less energetic than the oil that has not undergone such a change. Med: Uses. It has all the characteristic effects of prussic acid, but is so powerful and dangerous as to preclude its application. It is principally sold to perfumers and confectioners.

It is generally obtained by distilling the expressed cake of bitter almonds; 432the operation however requires considerable pharmaceutical address, and is, moreover, attended with unpleasant consequences.^[581]

OLEUM OLIVÆ. L.E.D. Olive Oil.

Qualities. Colour, pale yellow, somewhat inclining to green; Taste, bland; Odour, none; it ought to congeal at 38° Fah. With the exception of the oil of Almonds, it is the lightest of the fat oils, its specific gravity being only ·915. According to the recent observations of Dr. Clarke of Cambridge, this oil crystallizes in rectangular four-sided prisms with square bases. Uses. Although much less laxative than Castor oil, it is a useful aperient. It was long regarded, but erroneously, as possessing antidotal powers against the bites of venemous snakes and insects; and it has been confidently recommended, in the form of liniment, as a remedy against the Plague. Officinal Preparations. Linimentum Ammoniæ Fortius. L. Adulterations. It is not unfrequently mixed with the oil of poppy seeds, (see Papaveris Capsulæ), a fraud which may be easily discovered by exposing a sample to the freezing temperature, when the olive oil will congeal, while that of poppies will remain fluid; and since those oils which freeze with most difficulty are most susceptible of rancidity, the admixture of poppy oil must be regarded as injurious: it also deserves notice that the peculiar habitudes of Oil of Olives, with the Pernitrate of Mercury, offer a distinguishing character, by which the adulteration of the oil may be satisfactorily detected; for if the pernitrate, made by dissolving 6 parts of the metal in 7·5 of nitric acid, of sp. grav. 1·36, at a common temperature, be mixed with olive oil, the mixture, if kept cold, will in the course of a few hours become solid, whereas if it has any admixture of the oil of grains, it will not undergo such a change. The contamination derived from lead, which is frequently immersed in the oil for the purpose of removing its rancidity, may be detected by shaking one part of the suspected sample with three parts of water, impregnated with sulphuretted hydrogen, in a stopped phial.

433OLIBANUM. L.D.

Juniperus Lycia. Gummi-resina.

Olibanum.^[582]

Qualities. Form, fragments of a translucent, whitish yellow, and generally powdered with a whitish dust, occasioned by the friction of the pieces against each other; Odour, when burning is fragrant; Taste, bitterish and acrid. Solubility. When triturated with water, a milky solution results, which after some time deposits the resinous part, and retains not more than three-eighths dissolved. Alcohol dissolves three-fourths of it, and forms a solution perfectly transparent. Æther dissolves more than half, leaving a white opaque residuum soluble in water. Chemical Composition. The latest analysis of this substance is by Braconnot, who found in 100 parts of it, of volatile oil 8, resin 56, gum 39, and of an anomalous principle resembling gum, but insoluble in water and alcohol, 5·2 parts. The oil, in colour and smell, very strongly resembled that of lemons. Med. Uses. It is now less used than formerly; it is however stimulant and diaphoretic. Pulverized it enters into several popular electuaries for gleets, fluor albus, &c. and very probably acts by finding a passage into the urine, without undergoing any change or decomposition.

OPIUM. L.E.D. (Papaver Somniferum.) Capsularum immaturarum Succus concretus. (Turcicus.)

Turkey Opium.^[583]

Two kinds are found in commerce, distinguished by the name of Turkey and East India Opium.

Qualities. Form, Turkey opium occurs in flat pieces, of a solid compact texture, and possessing considerable tenacity; Sp. gr. 1·336, so that, when compared with the condensed juices of other plants, it is heavy, being exceeded only in this respect by opoponax and gum-arabic. By long exposure to the air it becomes hard, breaks with a glimmering fracture, owing to the presence of a few saline particles, and affords a yellowish powder. It is opaque, tenacious, plastic, adherent to the fingers. Colour, a reddish-brown, or fawn. Odour, peculiar, heavy, and narcotic. Taste, at first a nauseous bitter, which soon becomes acrid with some degree of warmth. It is inflammable, but yields no narcotic odour on burning. Solubility. It is partially soluble in water, alcohol, æther, wine, vinegar, and lemon juice; when triturated with hot water, five parts in twelve are dissolved, six suspended, and one part remains perfectly insoluble and resembles gluten. By long boiling, its soporific powers are impaired and 434ultimately destroyed: the alcoholic is more highly charged with its narcotic principle than the aqueous solution; but spirit, rather below proof, is its best menstruum. The watery solution when filtered is transparent, and reddens the colour of litmus; it undergoes no change on the addition of alcohol, but precipitates occur from pure ammonia and from the carbonates of fixed alkalies; from the solutions of oxy-muriate of mercury, nitrate of silver, sub-acetate and acetate of lead, the sulphates of copper, zinc, and iron, and from an infusion of galls. Chemical Composition. Resin, gum, bitter extractive, sulphate of lime, gluten, Narcotine (see note) and a peculiar alkaline body, to which the soporific virtues of opium are owing, and to which the appropriate name of Morphia has been assigned; and it appears moreover that this new alkaline body exists in combination with an unknown acid, which has therefore been denominated the Meconic Acid; so that the narcotic principle of opium is Morphia in the state of a meconiate, or perhaps of a super-meconiate.

For these important facts we are indebted to the successive labours of Derosne,^[584] Seguin,^[585] Sertuerner,^[586] and Robiquet. And the French codex contains, in its appendix, formulæ for the preparation of morphia^[587] according 435to the directions of these two latter chemists: viz. Robiquet’s process. Three hundred parts of pure opium are to be macerated during five days, in one thousand parts of common water; to the filtered solution, fifteen parts of perfectly pure magnesia (carefully avoiding the carbonate,) are to be added; boil this mixture for ten minutes, and separate the sediment by a filter, washing it with cold water until the water passes off clear; after which, treat it alternately with hot and cold alcohol, (12, 22, Bé.) as long as the menstruum takes up any colouring matter; the residue is then to be treated with boiling alcohol (22, 32, Bé.) for a few minutes. The solution, on cooling, will deposit crystals of Morphia.

Rationale of the Process. A soluble Meconiate of Magnesia is formed, whilst the sediment consists of Morphia in the state of mixture, with the excess of magnesia; the boiling alcohol with which this residuum is treated, exerts no action upon the magnesia, but dissolves the Morphia, and on cooling surrenders it in a crystalline form. A repetition of the treatment with boiling alcohol will procure a fresh crop of crystals, and the process should be continued until they cease to appear.

Sertuerner’s method. It differs from the preceding, in substituting ammonia for magnesia, and in adding to the sediment, separated as before mentioned, as much sulphuric acid as is sufficient to convert the Morphia into a sulphate, which is subsequently decomposed by a farther addition of ammonia; the precipitate thus produced is then dissolved in boiling alcohol, which on cooling surrenders the Morphia in a state of crystalline 436purity. It appears however that the Morphia produced by this latter method, is less abundant and more impure and coloured, than that which is furnished by the process of Robiquet.

Characters of Morphia. When pure, it crystallizes in very fine, transparent, truncated pyramids, the bases of which are either squares or rectangles, occasionally united base to base, and thereby forming octohedra. It is sparingly soluble in boiling water, but dissolves abundantly in heated alcohol; and the solution is intensely bitter; in æther it is far less soluble. It has all the characters of an alkali; affecting test papers, tinged with turmeric or violets; uniting with acids, and forming neutral salts, and decomposing the compounds of acids with metallic oxides. It unites with sulphur by means of heat, but the combination is decomposed at the same instant; it is incapable of forming soap with an oxidized oil. It fuses at a moderate temperature, when it resembles melted sulphur, and like that substance, crystallizes on cooling; it is decomposed by distillation, yielding carbonate of ammonia, oil, and a black resinous residue, with a peculiar smell; when heated in contact with air, it inflames rapidly; the voltaic pile exerts but little action upon it, yet, when mixed with a globule of mercury, the latter appears to become increased in bulk, and to change consistence. When analyzed by means of the deutoxide of copper, it yields carbon, hydrogen, and oxygen; and if ammonia has been employed, as a precipitant in its preparation, we shall also obtain some nitrogen, but not if prepared according to the improved process of Robiquet. Its habitudes with different bodies have not hitherto been sufficiently investigated, but they are highly important, in as much as they will explain the operation of those various medicinal compounds, into which opium enters as a principal ingredient. Sertuerner has given us an account of the effect of the alcoholic solution of Morphia on himself and three of his pupils; he found, that repeated small doses of half a grain produced at first decided excitation; then weakness, numbness, and tendency to fainting; after swallowing vinegar while in this condition, violent vomiting was excited, profound sleep intervened in one delicate individual, and next day he suffered from nausea, vomiting, head-ache, anorexia, constipation, and heaviness (Ann. de Chim. et de Phys. T. v.) This case is sufficient to shew that although Morphia possesses the characteristic powers of opium, its strength is by no means commensurate with its supposed concentration. When uncombined it exerts little or no action in consequence of its insolubility. The following history of its saline compounds may be useful.

The Carbonate crystallizes in short prisms.

The Acetate in needles, very soluble, and extremely active.

The Sulphate, in arborescent crystals, very soluble.

The Muriate, in plumose crystals, much less soluble; when evaporated, it concretes into a shining white plumose mass on cooling.

The Nitrates, in prisms grouped together.

The Meconiate, in oblique prisms, sparingly soluble.

The Tartrate, in prisms.

Morphia is separated from the above combinations by ammonia.

Morphia is very soluble in olive oil, and according to the experiments of M. Majendie, the compound acts with great intensity; with extractive matter, it forms a compound which is almost insoluble in water, but very soluble in acids.

The solubility of Morphia in acids explains why the administration of vinegar increases the powers of opium, (see page 135.) M. Majendie 437considers Morphia to produce a more purely soporose effect than opium, and that it is moreover exempt from the consecutive operation which so generally renders opium objectionable. This opinion, however, has not been confirmed by the trials made in this country; equally gratuitous is the assertion of the same physiologist, that by ringing changes on the salts of Morphia, its hypnotic effects may be kept up without increasing its dose.

As M. Majendie considers the after effects of opium to be independent of Morphia, it was necessary for him to point out the particular principle from which these noxious consequences arose, and he accordingly ascribed them to the Salt of Derosne, now more usually denominated Narcotine, and which may be entirely removed from the extract of opium by macerating it in sulphuric æther; and in this way, it is said, a preparation is obtained, which, like Morphia, is exempt from the occasional bad consequences of the common drug; but no satisfactory trials have as yet been made with it.

The Meconic acid, when separated from the residuum of the magnesian salt, as described above, does not appear to possess any medicinal activity. Its distinguishing chemical character is, that it produces an intensely red colour in solutions of iron oxidized ad maximum.

East India Opium is an inferior species;^[588] it differs from Turkey Opium, in its texture being less compact, and much softer; its colour darker; its narcotic odour fainter, but combined with a strong empyreuma, and in its taste being more bitter, but less acrimonious. According to the experiments of Mr. A. T. Thomson, Turkey Opium contains three times more morphia than the East Indian variety. This latter, when triturated with water, is taken up without any residuum; hence it contains no gluten, but the sulphate of lime is more abundant, as appears from the relative proportion of precipitate produced by oxalic acid. The solution of the acetate of barytes, whilst it occasions no disturbance in the solutions of the Turkey variety, produces a copious precipitate with the East Indian.

Med. Uses. Are so well known that a few practical remarks will suffice.^[589]

Chemistry, it appears, has developed the principle of its activity, and accumulated experience has established the value and importance of its medicinal applications, but Physiology is still unable to demonstrate the manner in which it produces its effects. It must be admitted that its primary operation is that of a powerful and diffusible stimulant, but it is immediately followed by narcotic and sedative effects, which are far greater than could have been inferred from the degree of previous excitement, and hence much keen controversy has arisen in the schools concerning its modus operandi, (see page 76.) In large doses, the primary excitement is scarcely apparent, but the powers of life are instantly depressed, drowsiness and stupor succeed, and when the dose is excessive, these are followed by delirium, stertorous breathing, cold sweats, convulsions, and apoplectic death. Its stimulant effects are apparent only in small doses, by which the energy of the mind,^[590] the strength of the pulse, and the heat of the 438body, are considerably increased, but all the secretions and excretions, except the cuticular^[591] discharge, are diminished; for example, the fæces of persons, after the use of opium, are not unfrequently clay-coloured, from the suspension of the biliary secretion; this circumstance suggests some important precautions with respect to its exhibition. Opium, when properly directed, is capable of fulfilling two great indications; 1st, of supporting the powers of life, and 2nd, of allaying spasm, pain, and irritation, and of blunting that morbid susceptibility of impression, which so frequently attends fever. Its use is contra-indicated in all cases where inflammatory action prevails, as in pulmonary affections, attended with an accelerated circulation and a dry hard cough.^[592] It is employed by some of the oriental nations for the same purposes that we take spirituous potations: by the Turks especially, to whom our more generous beverages are prohibited by religious prejudice, opium is solicited to inspire courage, or to invigorate fortitude;—to soothe sorrow;—or to dissipate the remembrance of misfortune;—to awaken the fancy to more brilliant exertions; or to create that mild composure and serenity of feeling, which is desirable after the cares and solicitudes of an active, perplexing, and arduous scene: like spirituous liquors among other people, it is, in short, the support of the coward,—the solace of the wretched,—and the daily source of intoxication to the debauchee. Notwithstanding all this, spirit and opium are by no means parallel medicines; on the contrary, the latter substance offers the best remedy for the Mania a Potu, and in cases of habitual drunkenness from alcohol, where our wish is to abstract the spirit, but are for obvious reasons unable so to do, we may frequently alternate its use with that of opium, with considerable advantage. Many of the beneficial effects of this remedy are to be referred to its power of allaying irritability; Sir G. Blane has remarked, that in ill-conditioned ulcers in the West Indies, opium 439was found superior to all other internal medicines for producing a disposition to heal. Under the free use of it, such ulcers would in place of a sanious discharge produce a healthy puss succeeded by granulations and cicatrization. It appears to do this by suspending irritation, and perhaps by promoting absorption.