PHARMACOLOGIA. (continued 4)

1. Watery or Simple Extracts.

Mucilaginous Extracts of Rouelle.

These extracts must, of course, contain all the principles of a plant which are soluble in water, such as gum, extractive matter, tannin, cinchonin, sugar, fecula, &c. together with any soluble salts which the vegetable may contain. I have also found by experiment that an aqueous extract may even contain, in small proportions, certain elements which, although quite insoluble in water, are nevertheless partially soluble in vegetable 363infusion. This law of vegetable chemistry has never been expressed, although we have repeated instances of its truth, and a knowledge of it may explain some hitherto unintelligible anomalies. It has been stated that extractive matter is perfectly insoluble in æther, but Mr. A. Thomson found repeatedly, that if a small portion of resin was present, æther would in that case take up extractive in combination with the resin which it so readily dissolves. As decoction or infusion is a process preliminary to that of extraction, the practitioner must refer to those articles for an enumeration of the different sources of error which are attached to them.

Extractum Aloes Purificatum. L. The resinous element of the aloes is got rid of in this preparation; on which account it is supposed, in an equal dose, to be more purgative and less irritating. Dose, gr. x to xv. Form: 12, 13, 36.

Extractum Anthemidis. L.E. Extract. Florum Chamœmeli. D. This extract furnishes an example of the change effected on some plants by the process of extraction; in this case the volatile oil is dissipated, and a simple bitter remains, possessing scarcely any of the characteristic properties of chamomile. This remark, however, does not apply to this extract, when prepared in vacuo. I have lately received from Mr. Pope of Oxford Street, a specimen which retains, in the most eminent degree, all the odour and taste of the recent flower. Dose, gr. x–℈j.

Extractum Cinchonæ. L.D. The properties of the bark in this preparation are much invalidated, owing to the oxidizement of its extractive matter, which takes place to such an extent, that not more than one half of the preparation is soluble in water; it is not however altogether devoid of utility, and will often sit lightly on the stomach, when the powder is rejected. Its taste is very bitter, but less austere than the powder. The most beautiful extract of bark, which I have ever seen, was prepared by Mr. Barry of Plough Court; its colour was that of a deep brilliant ruby, and its flavour preserved all the characteristic peculiarity of the recent substance.^[499] Dose, grs. x to ʒss. Fourteen ounces of the bark will yield about three ounces and a half of extract. It should be kept soft, so as to be fit for forming pills, and hard, so that it may be reduced to powder.

Extractum Colocynthidis. L. This extract is much milder, although less powerful, than the pulp; Dose, grs. v to ʒss. It soon becomes hard and mouldy.^[500]

Extractum Gentianæ. L.E.D. The bitter principle suffers no deterioration in the process: it is used principally as a vehicle for metallic preparations. Form. 36, 53, 103. Dose, gr. x to ℈j.

Extractum Glycyrrhizæ. L.D. It is usually imported from Spain; 364in the coarser kinds, the pulps of various plums and of prunes are added; it should dissolve in water without leaving any feculence.^[501]

Extractum Hæmatoxyli. L.E.D. The astringent properties of the logwood are preserved in the extract, but it becomes so extremely hard, that pills made of it very commonly pass through the body without undergoing the least change. Dose, grs. x to ʒss dissolved in cinnamon water: it sometimes imparts a bloody hue to the urine of those who have taken it.

Extractum Humuli. L. The bitter taste of the hop characterises this preparation; whether it possesses, or not, any anodyne properties, seems very doubtful. Dose, grs. v to ℈j.

Extractum Opii. L.D. As it contains less resinous matter than crude opium, it is supposed to produce its effects with less subsequent derangement. See Opium. Dose, gr. j to v, for an adult.

Extractum Papaveris. L.D. It is a weak opium. Dose, grs. ij to ℈j.

Extractum Sarsaparillæ. Notwithstanding the reputation which this preparation has acquired, it is very doubtful whether it possesses any medicinal powers. Dose, gr. x to ʒj in pills, or dissolved in the decoction.

Extractum Stramonii. This extract was first recommended by Stöerck, as a powerful remedy in maniacal affections; its probable value in such diseases appears to have been suggested by a very curious process of reasoning, viz. that as it deranged the intellect of the sane, it might possibly correct that of the insane. Experience has certainly not confirmed the very sanguine report of Stöerck with regard to its powers, but it has satisfactorily shewn its occasional value in violent paroxysms, in quieting the mind, and procuring rest. I am informed by my friend Dr. Davy, that, for such an object, it has been very frequently and successfully given, in the Lunatic Military Hospital at Fort Clarence. He farther states that he has himself made many trials with the extract of Stramonium, prepared by Mr. Barry (in vacuo) as well as with the common extract; and that he finds the former to be uniformly more powerful. “In most diseases,” says he, “this medicine would seem uncertain in its operation, sometimes occasioning an anodyne effect, and, at other times, producing irritation, and preventing sleep; I have, however, seen very beneficial effects from it in asthma, and in coughs that have a nightly exacerbation, in doses of from gr. 1/4 to gr. 2, daily.”

Extractum Taraxaci. L.D. The medicinal powers of Dandelion are asserted to exist unimpaired in this preparation, but it becomes inert by keeping. See Taraxacum. Dose. grs. x to ʒj, in combination with sulphate of potass.

2. Spirituous or Resinous Extracts.

These may contain, with the exception of gum, all the ingredients contained in watery extracts, besides resin; their composition however will 365greatly depend upon the strength of the spirit employed as the solvent; but of this I shall speak more fully under the article Tincture.

Extractum Cinchonæ Resinosum. L.E.D. The operation of spirit in this preparation is two-fold; it extracts from the bark the element which is insoluble in water, and it diminishes the tendency in the extractive matter to absorb oxygen during the process. Dose, grs. x to xxx. It is said that a spurious extract of bark is to be met with in the market, consisting of the extract of the horse-chesnut tree bark, and yellow resin.

Extractum Colocynthidis compositum. L.D. Extract. Catharticum. P.L. 1775. Pilulæ Rudii. P.L. 1720. This preparation has been established through successive pharmacopœias, and has undergone some modification in each; in the present edition the soap has been restored, and its solubility is thereby increased, as well as its mildness as a cathartic. The omission of this ingredient was formerly suggested by the consideration of its being incompatible with Calomel; this however is not the case. It presents a combination of purgative substances which is highly judicious, and will be found to be more powerful than an equivalent dose of any one of the ingredients. Dose, gr. v to ʒss, Form. 71, 81, 88.

Extractum Jalapæ. L.E.D. It is purgative, but is liable to gripe, unless it be triturated with sugar and almonds, or mucilage, so as to form an emulsion. Dose, grs. x to ℈j.

Extractum Rhei. L. The powers of the Rhubarb are considerably impaired in this extract. Dose, grs. x to ʒss. Form. 78.

3. Inspissated Juices.

These preparations are obtained by expressing the juices from fresh plants, and evaporating them in a water-bath; they are generally of a lighter colour than common extracts, and they are certainly much more active, although there is a great difference in the activity of different samples; and perhaps the medicinal powers of the juices themselves are very much under the controul of soil and season. That they vary in quantity from such causes we have ample proof; thus in moist seasons, Beaumé obtained five pounds of inspissated juice from thirty pounds of elder berries, whereas, in dry seasons, he could rarely get more than two. From hemlock he procured in October, 1796, 7·5 per cent. of inspissated juice, and in May of the same year only 3·7; on the contrary, in August, 1768, 4 per cent., and in May, 1776, as much as 6·5; but in general, the product in the autumnal months was the most considerable.

The modes of preparing the inspissated juices of the same plant vary in the different pharmacopœias, and in several points that are very essential; some direct the expressed juices to be immediately inspissated, others allow them to undergo a slight degree of fermentation, and some defecate them, before they proceed to their inspissation.

Extractum (Succus Spissatus. E.) Aconiti. L.E. The medicinal properties of this preparation are analogous to those of the recent Wolfsbane, viz. narcotic, and in some cases diuretic, (see Form. 128.) It is however rarely used. Dose, at first, should not exceed gr. ½, but it may be gradually increased. I have not yet, says Dr. Davy, in a letter recently received from him, had much experience of the Extractum Aconiti, but that little is favourable to its use; “in some cases of chronic rheumatism, and in some of intermittent fever, complicated with visceral disease, it has had 366a beneficial effect not to be mistaken; the dose has been from one to two grains.” Dr. Stöerck, who first tried this medicine, observed from it a powerful diaphoretic effect; this, says Dr. Davy, “I have not noticed, and yet the extract which I have used was prepared by Mr. Barry, in vacuo, which is certainly far more powerful than that employed by Stöerck; the latter, when applied to the tongue, “levissimam tantum titillationem excitabat,” whereas that of Mr. Barry produces a most disagreeable sensation of burning, which extends to the throat; and in one instance, when applied to the tip of my tongue, it occasioned ulceration.”

Extractum Belladonnæ. L.E. See Belladonnæ Folia. Dose, gr. j, gradually increased to gr. v, in the form of pill. Dr. Davy has made a few trials of Barry’s Extract; the results of which he informs me are not at all favourable to the use of this medicine; it is much more powerful than the common extract, and can only be given with safety in small doses; “in several instances,” says he, “I have not been able to repeat a grain dose daily, more than thrice, on account of the alarming symptoms produced, as head-ache, vertigo, indistinct vision with dilated pupil, and, in one case, irritation of the bladder, occasioning very frequent micturition; in chronic rheumatism and catarrh, with severe cough, the only diseases in which I have yet given it, it has not appeared to be in the least serviceable; it may probably prove valuable to the oculist; from trials that have been made of it here by Mr. Miller, Assistant Surgeon to the Forces, it has been found to dilate the pupil beyond the common extract. Stöerck even introduced his extract into the eye with impunity. Acrid as the preparation is which I have used, the patients have never complained of it, nor have I known any disagreeable effects from it, when applied in solution, sufficiently dilute.”

Extractum (Succus Spissatus. E.D.) Conii. L. Much of this extract, as it is found in commerce, has not been prepared with equal fidelity, nor with due attention to the season when the plant is in its greatest perfection; Dr. Fothergill says, “I know from repeated experiments, that the extract which has been prepared from hemlock, before the plant arrives at maturity, is much inferior to that which is made when the plant has acquired its full vigour, and is rather on the verge of decline: just when the flowers fade, the rudiments of the seeds become observable, and the habit of the plant inclines to yellow, is the proper time to collect it;” the plants which grow in places exposed to the sun should be selected, as being more virose than those that grow in the shade: still however with every precaution, it will always be uncertain in strength. Orfila found that an extract prepared by boiling the dried powder in water, and evaporating the decoction, was inert; in fact, the whole of the activity of the plant resides in a resinous element insoluble in water, and for which I have proposed the name of Conein. Extract of hemlock, when judiciously prepared, is a very valuable sedative; I state this from ample experience, and when combined with Hyoscyamus, and adapted by means of mucilage and syrup, to the form of a mixture, it affords a more effectual palliative than any remedy with which I am acquainted, for coughs and pulmonary irritation. Form. 19. is that from which I have derived the greatest benefit in such cases. See also Form. 2, 3, 4, 19, 57. Since the fourth edition of the present work, I requested my friend Dr. John Davy to make trial of its efficacy in the Military Hospital at Chatham, and I here introduce his report upon the subject;—“My experience of 367the effects of the Extractum Conii perfectly agrees with that of Dr. Paris, as stated in the fourth edition of the Pharmacologia, and I am of his opinion that when properly prepared, and administered, it is a very valuable sedative; I have given it to the extent daily of from a scruple to a drachm, in chronic catarrh, and in phthisis pulmonalis, either alone or in conjunction with the Extract of Hyoscyamus, and it has afforded more relief than any other medicine that I have tried. From two or three trials of it in pneumonia, I am disposed to think it may be very serviceable in certain forms of this disease, in which venesection is contra-indicated by extreme debility; and also in measles. In the trials alluded to, I commenced giving it in the large dose of a drachm, daily, suspended in water containing in solution a grain of Antimonium Tartarizatum. In a very few instances, where I have from the commencement given it in a large dose, as from ʒj to ʒiss, it has occasioned hallucination of ideas, which in two cases was attended with excitement of the sensorium and increased action of the heart, and in one case, with diminished activity of both. The Extract of Conium, prepared by Mr. Barry, is the most powerful one I have ever used, indeed, until I tried it, I had no just idea of the virtues of Conium as a medicine; but I am now disposed to give credit to Stöerk’s account of its efficacy in various chronic diseases; and I have no doubt but that this valuable medicine has fallen into comparative disrepute and disuse from the bad quality of the extract commonly employed.” Dr. Maton has found that the value of this extract is greatly increased by including the seeds in its preparation. Dose, grs. v to ℈j; or more, twice or thrice a day; in a full dose it produces giddiness, a slight nausea, and a tremor of the body; a peculiar heavy sensation is also experienced about the eyes; and the bowels become gently relaxed: unless some of these sensations are produced, we are never sure that the remedy has had a fair trial of its effects. Patients will generally bear a larger dose at night than at noon, and at noon than in the morning.

Extractum Elaterii. L. This substance spontaneously subsides from the juice of the wild cucumber, in consequence I presume of one of those series of changes which vegetable matter is perpetually undergoing, although we are hitherto unable to express them by any known chemical law. It is therefore not an extract, either in the chemical or pharmaceutical acceptation of the term, nor an inspissated juice, nor is it a fecula,^[502] as it has been termed; the Dublin College has perhaps been more correct in simply calling it Elaterium, the name given to it by Dioscorides.

It occurs in commerce in little thin cakes, or broken pieces, bearing the impression of the muslin upon which it has been dried; its colour is greenish, its taste bitter, and somewhat acrid; and when tolerably pure, it is light, pulverulent, and inflammable.

The early history of this medicinal substance is involved in great perplexity, each author speaking of a different preparation by the same name; for instance, the Elaterium of Dioscorides must have been a very different substance from that of Theophrastus; and, wherever Hippocrates mentions the term, he evidently alludes to any violent purgative. “Hippocrati 368Elaterium medicamentum est quod per alvum expurgat.” (Bod: in Theophrast.) This will, in some degree, reconcile the discordant testimonies of different authors with regard to the powers of Elaterium; for example, Dioscorides states its dose to be from grs. ii to ℈j—in Ætius, Paulus, and Actuarius, it is recommended to the extent of ʒss—in Mesue from ℈ss to ℈j—in Bontius (Med: Ind:) from ℈j to ʒss—Massarias exhibits it in doses of gr. vj—Fernelius and Sennertus to ℈j—Herman from grs. v vj—Quincy to grs. v—and Boerhaave does not venture to give more than gr. iv—while the practitioners of the present day limit their dose from gr. ½ to grs. ij. Dr. Clutterbuck, with a laudable intention to discover some method of procuring this article at a cheaper rate, and at the same time of establishing some process which might ensure a preparation of more uniform strength, has lately performed a series of interesting and instructive experiments,^[503] the results of which prove in a satisfactory manner “that the active principle of this plant is neither lodged in the roots, leaves, flowers, nor stalks, in any considerable quantity: nor is it to be found in the body of the fruit itself, or in the seeds, but in the juice around the seeds; the substance which spontaneously subsides from this liquor, obtained without pressure, is genuine Elaterium, the quantity of which, contained in the fruit, is extremely small, for Dr. Clutterbuck obtained only six grains from forty cucumbers.” This gentleman communicated the detail of these experiments to the President of the College of Physicians, who requested me, as professor of Materia Medica, to report upon them. I accordingly deemed it to be my duty to enter upon a series of new experiments, which I have lately completed, with the able assistance of Mr. Faraday, in the laboratory of the Royal Institution. The results of which will shew, that although Dr. Clutterbuck found that an eighth part of a grain of elaterium seldom failed to purge violently, yet, strange as it may appear, that not more than one grain in ten of elaterium, as it occurs in commerce, possesses any active properties, and that this decimal part is a vegetable proximate principle, not hitherto noticed, to which I shall give the name of Elatin. I shall subjoin the detail of my experiments, and I think it will appear that their results will authorise me to express the chemical composition of Elaterium in the following manner.

F. Water ·4

I. { B. Extractive 2·6

B.DJ Fecula 2·8

C. Gluten ·5

K. Woody matter 2·5

H. Elatin { 1·2

G. Bitter Principle

10 grains.

369Proximate Analysis of Elaterium.

Experiments. Series 1st.

A.

Ten grains of Elaterium, obtained from a respectable chemist, and having all the sensible properties which indicated it to be genuine, were digested for twenty-four hours with distilled water, at a temperature far below that of boiling; four grains only were dissolved.

B.

The solution was intensely bitter, of a brownish yellow colour, and was not in the least disturbed by alcohol, although a solution of Iodine produced a blue colour; the solution therefore contained no gum, and only slight traces of starch.

C.

The solution, after standing twenty-four hours, yielded a pellicle of insoluble matter, which when burnt appeared to resemble Gluten.

D.

The six grains which were insoluble in water, were treated for forty-eight hours with alcohol of the specific gravity ·817, at 66° of Fahrenheit; a green solution was obtained, but by slow evaporation only half a grain of solid green matter was procured. The insoluble residue obstinately adhered to, and coated the filtre like a varnish, and completely defended the mass from the action of the alcohol; it is probable that it consisted principally of Starch.

Experiments. Series 2d.

E.

Ten grains of Elaterium, from the same sample, were treated with alcohol of the specific gravity ·817, at 66° Fahrenheit, for twenty-four hours; upon being filtered, and the residuum washed with successive portions of alcohol, the Elaterium was found to have lost 1·6 of a grain. The high specific gravity of the alcohol in this experiment was important; had it been lower, different results would have been produced.

F.

The alcoholic solution obtained in the last experiment, was of a most brilliant and beautiful green colour, resembling that of the oil of cajeput, but brighter; upon slowly evaporating it, 1·2 grains of solid green matter were obtained.

G.

The solid green matter of the last experiment was treated with boiling distilled water, when a minute portion was thus dissolved, and a solution of a most intensely bitter taste, and of a brownish yellow colour, resulted.

H.

The residue, insoluble in water, was inflammable, burning with smoke and an aromatic odour, not in the least bitter; it was soluble in alkalies, and was again precipitated from them unchanged in colour; it formed, with pure alcohol, a beautiful tincture, which yielded an odour of a very nauseous kind, but of very little flavour, and which gave a precipitate with water; it was soft, and of considerable specific gravity, sinking rapidly in water; circumstances which distinguish it from common resin; in very minute quantities it purges. It appears to be the element in which the purgative powers of the Elaterium are concentrated, and which I have denominated Elatin.

370I.

The residuum, insoluble in alcohol, weighing 8·4 grs. (Expt. E) was boiled in double distilled water, when 5·9 grs. were dissolved.

J.

The above solution was copiously precipitated blue by a solution of Iodine, and was scarcely disturbed by the Per-sulphate of Iron.

K.

The part insoluble, both in alcohol and water, which was left after Experiment I, amounting to 2·5 grains; it burnt like wood, and was insoluble in alkalies.

It appears that the whole of the Elatin does not separate itself from its native juice by spontaneous subsidence, and that, on this account, the supernatant liquor possesses some powers as a cathartic. We cannot be surprised therefore that the Elaterium of commerce should be a very variable and uncertain medicine; for independent of the great temptation which its high price holds out for adulterating it, which is frequently done with starch, it necessarily follows that where the active principle of a compound bears so small a proportion to its bulk, it is liable to be affected by the slightest variation in the process for its preparation, and even by the temperature of the season; where pressure is used for obtaining the juices, a greater or less quantity of the inactive parts of the cucumber will be mixed with the Elatin, in proportion to the extent of such pressure, and the Elaterium will of course be proportionally weak.^[504] There is one curious result obtained in my experiments which deserves notice, viz. that there is a bitter principle in the Elaterium, very distinct from its extractive matter, and totally unconnected with its activity, for I diluted the solution obtained in experiment G. and swallowed it, but it produced upon me no effect, except that which I generally experience upon taking a powerful bitter,—an increased appetite; and yet notwithstanding this fact, when in combination with Elatin, it is far from being inert, since this latter body is considerably quickened by its presence. See page 152. The solution B was given to a person, but no effect whatever ensued. Dose of good Elaterium, as it occurs in commerce, is about one grain, or it is better to give it only to the extent of half a grain at a time, and to repeat that dose every hour until it begins to operate. It is probably, when thus managed, the best hydragogue cathartic which we possess; it differs however from the class of remedies to which it belongs, for it excites the pulse and whole animal system, so as to produce a considerable degree of febrile action. It was strongly recommended by Sydenham, Lister, and Hoffman, 371and all their cotemporaries and immediate successors, as a valuable remedy in dropsy; but in consequence of some fatal results from its improper application, it was driven from practice with a violence that marks prejudice rather than conviction; one author, in descanting upon its virulence, exclaims, “Elaterium esse in catalogo diaboli quo necat homines.” For its restoration to medicine, we are indebted to Dr. Ferriar of Manchester, who used it with great success in the cure of Hydrothorax.

Extractum (Succus Spissatus. E.D.) Hyoscyami. L. This preparation is certainly powerfully narcotic, and tends to relax rather than astringe the bowels; where the constitution is rebellious to opium, it furnishes a more valuable resource to the practitioner than any other narcotic extract. Dose, gr. v to ℈j, in pills. See Form. 1, 3, 4, 19, 139.

Extractum Lactucæ. L. Succus Spissatus Lactucæ Sativæ. E. This preparation has found its way into the London Pharmacopœia, in consequence of the testimony of many highly respectable practitioners in favour of its sedative properties. In the memoirs of the Caledonian Horticultural Society, various suggestions are offered as to the best mode of obtaining an extract from the milky juice of the garden Lettuce, to which Dr. Duncan has bestowed the name of “Lactucarium;” it was first recommended to take the milk with cotton, afterwards with a sponge, and more recently with a painter’s brush; all these methods however are attended with considerable difficulty, and the juice cannot be collected in any quantity. Mr. Probart, a chemist in Great Portland Street, has lately cultivated large plantations of the lettuce, for the purpose of instituting experiments upon the subject, and I am happy in being enabled through his liberality, to introduce in this place, an account of the process which he pursues, and which he considers the only one by which the article can be brought into the market at any reasonable price.^[505]

372In concluding the history of Inspissated juices, it deserves notice that the London College uniformly directs that the feculence should be preserved in the compound: there can be no doubt of the propriety of such advice, but the Colleges of Edinburgh and Dublin reject it. The French Codex gives directions for two extracts from each of these substances, one containing what they please to denominate the fecula, the other not; thus there is “Extractum Cicutæ absque Fecula” and “Extract: Cicut: cum Fecula.” There is one curious fact respecting these narcotic preparations, that most, if not all of them, contain nitre, common salt, and muriate of potass.

Manufacturing chemists, in order to give a smooth and glossy appearance to their Extracts, generally add to every ℔j, about ʒss of gum, fʒj of olive oil, and ♏︎xx of rectified spirit; there is no harm in the practice.

FERRI SUB-CARBONAS. L. Carbonas Ferri

Præcipitatus. E. Carbonas Ferri. D.

Carbonate of Iron.

In a former Pharmacopœia of London, a sub-carbonate of iron was prepared, under the name of ferri-rubigo (rust of iron,) by exposing iron-filings to the action of air and water; and although the Colleges of Edinburgh and Dublin still retain this mode of preparation, yet they admit at the same time of another which, like the sub-carbonate of the present London Pharmacopœia, is produced by precipitation. Qualities. Form, a chocolate brown powder. Odour, none. Taste, slightly styptic. Chemical Composition. Mr. Phillips has shewn that this precipitate is liable to vary according to the temperature at which it is prepared, as well as from other differences of manipulation; it generally consists of mixtures of peroxide, and proto-carbonate of iron, in the proportion of four parts of the latter, and six of the former. By referring to the Medicinal Dynameter the practitioner may find the quantity of those ingredients in any given weight of the preparation, and compare its strength with the other chalybeate medicines. Solubility. It is insoluble in water, but acids dissolve it with effervescence. Forms of Exhibition. In powder or pills, combined with aromatics. Dose, gr. v to xxx. (Form. 38.) It has 373lately been brought into particular notice by the publication of Mr. Hutchinson of Southwell, who states that in doses of half a drachm to a drachm, two or three times a day, it has proved in his hands a most efficacious remedy in the cure of Tic doloureux. Mr. Hutchinson is well known to the profession as a judicious and inquiring practitioner, and we are well satisfied that he would not recommend any remedy to the attention of his brethren, without a well grounded assurance of its efficacy; at the same time it must be remembered that this disease is very frequently the consequence of an irritation in some nerve, by the mechanical operation of osseous spiculæ; in such cases we cannot expect the sub-carbonate of Iron to afford relief. A noble Marquis who lost his leg at Waterloo, suffered excruciating pains in his face, in consequence of exfoliation in the stump, which were relieved as soon as the local irritation subsided; and a late lamented physician appears to have owed his severe sufferings to the irritation produced on the brain by a bony excrescence. I have little doubt if cases of Tic doloureux were more carefully examined, they would be frequently found to derive their origin from a similar source. If it were necessary I could add several of such instances to those already enumerated.^[506]

FERRI RAMENTA ET FILA. L. Fila et

Limatura. E. Ferri Scobs. D.

Iron Filings and Wire.

Iron seems to be a metal that proves active in its metallic state; its filings may be given in the form of powder, conjoined to some aromatic, or what is perhaps more eligible, in the form of an electuary. The Mahometan practitioners are in the habit of prescribing them, in conjunction with ginger, and cummin seeds, in cases requiring tonics. Dose, grs. v to ʒss. Impurities. Iron filings should be carefully purified by the application of the magnet, since those obtained from the work-shops are generally mixed with copper and other metals. For pharmaceutical purposes, iron wire should be preferred, as being the most pure, since the softest iron only can be drawn, and Mr. Phillips has shewn us, in his experiments upon the “Ferrum Tartarizatum” that soft iron is more easily acted upon by Tartar.

FERRI SULPHAS. L. Sulphas Ferri. E.D.

Ferrum Vitriolatum. P.L. 1787. Sal Martis. P.L. 1745.

Sal, seu Vitriolatum Martis. P.L. 1720.

Sulphate of Iron, formerly Green Vitriol.

Qualities. Form, crystals, which are rhomboidal prisms, transparent, and of a fine green colour; when exposed to the air they effloresce, and 374at the same time become covered with a yellow powder, owing to the attraction of oxygen; when exposed to heat, they undergo watery fusion, and at a higher temperature, the acid is driven off and the peroxide of iron alone remains, which in commerce is known by the name of Colcothar. Chemical Composition. According to Dr. Thomson, it consists of 27·7 of sulphuric acid, 28·3 of protoxide of iron, and 45 of water; 8 parts, however, of this water, exist in combination with the oxide of iron. The Medicinal Dynameter will shew the proportion of protoxide in any given weight of this salt. Solubility. It is soluble in two parts of water at 60°, and three-fourths at 212°. The solution reddens vegetable blues. It is insoluble in alcohol; when however the iron is farther oxidized, it becomes soluble in that menstruum.^[507] Incompatible Substances. Every salt whose base forms an insoluble compound with sulphuric acid; the earths, the alkalies and their carbonates; borate of soda; nitrate of potass; muriate of ammonia; tartrate of potass and soda; acetate of ammonia; nitrate of silver; sub-acetate and acetate of lead; and Soaps. Whether the medicinal virtues of a salt of iron are injured by combination with astringent vegetable matter, seems to admit of doubt. Such substances have been usually ranked amongst the incompatibles, but I am disposed to think without sufficient grounds, for I have frequently witnessed the salutary effects of iron when exhibited in this questionable state of combination—may not the absorbents be more disposed to take up iron, when combined with vegetable matter, than when it is presented in a more purely mineral form?^[508] Medicinal Uses. Tonic, astringent, emmenagogue, and anthelmintic; in large doses, it occasions griping in the bowels. Dose, gr. j to v, combined with rhubarb, or some bitter extract. (form: 72, 87.) If given in solution, the water should be previously boiled, or the oxygen contained in the atmospherical air, which is diffused through it, will partially convert the salt into an oxy-sulphat, and render it insoluble. As an external astringent it is useful in the aphthæ of children.^[509] Officinal Prep. Mist: Ferri comp: L. (K) Pil: Ferri comp: L. (J).

375FERRUM AMMONIATUM. L. Murias

Ammoniæ et Ferri. E.D.

Ferrum Ammoniacale, P.L. 1787. Flores Martiales.

P.L. 1745. Ens Veneris. P.L. 1720.

Qualities. Form, crystalline grains, which deliquesce; Colour, orange yellow; Odour, resembling that of saffron; Taste, styptic. Chemical Composition. This is very variable; depending upon the degree of heat and length of time employed for its preparation. It seems to be a mixed mass, consisting of sub-muriate of ammonia and sub-muriate of iron, the metal being in the state of red oxide; and, Mr. Phillips states that in the London preparation a portion of sub-carbonate of ammonia is necessarily present. The same chemist has also shewn that the proportion of Peroxide of iron in 200 grains is not more than three grains. Its equivalents will be seen in the Medicinal Dynameter. Solubility, f℥j of water dissolves ʒiv of it; it is also very soluble in alcohol. Incompatible Substances. The Alkalies, and their Carbonates; Lime water, and Astringent vegetables. Medicinal Uses. It is tonic, emmenagogue, and aperient, but it is so uncertain in its composition and effects that it is rarely used. Officinal Prep: Tinct: Ferri Ammon: L. Form: 36, 43, 95. Impurities. These are indicated by the dull and pale yellow colour of the salt; it may be purified by resubliming it.

FERRUM TARTARIZATUM. L.

Tartras Potassæ et Ferri. E.

Tartarum Ferri. D.

Qualities. Form, a powder of a brownish green colour; Odour, none; Taste, slightly styptic; it attracts humidity from the atmosphere, but does not deliquesce. Chemical Composition. Mr. Phillips has devoted much attention to this subject, and he states that as it is frequently prepared, it is a mere mixture of metallic iron with super-tartrate of potass, coloured by oxide of iron; when however it is made with more care, it appears to be a double salt, consisting of tartrate of potass and tartrate of iron; or may it not be one of those combinations which cream of tartar forms with metals, and of which I have spoken under the article Antimonium Tartarizatum? The quantity of peroxide of iron contained in any weight of this preparation may be seen by referring to the Medicinal Dynameter; five grains, for instance, will be found to contain gr. j of peroxide, which, it will be observed, are equivalent to ♏︎xiv of the Tinctura Ferri Muriatis, and to ♏︎xxv of the Liquor Ferri Alkalini, or to f℥j of the Vinum Ferri. Solubility. It is very soluble in water, and the solution remains for a great length of time without undergoing any change, except that of depositing tartrate of lime, which is an incidental impurity in the super-tartrate of potass. Incompatible Substances. All strong acids; lime water; hydro-sulphuret of potass; astringent vegetables? The fixed alkalies and 376their carbonates decompose the solution very slowly, unless heated; but ammonia and its sub-carbonate produce upon it no effect, whether it be hot or cold; this fact, observes Mr. Phillips, will enable us to exhibit iron in solution with an alkali, without the occurrence of an precipitate. Forms of Exhibition. The perfect preparation, from its tendency to deliquesce, cannot be well ordered in the form of powder; that of solution is probably the most judicious. Med. Uses. It is supposed to add to its chalybeate virtues those of a diuretic nature. Dose, grs. x to ʒss. See Form: 34, 53, 92. Dr. Bateman has recommended a watery solution of it, as a chalybeate peculiarly suited to children, from its tasteless quality.^[510]

FILICIS RADIX. L.E.D.

(Aspidium Filix, Mas.)

Root of the Male Fern.

Qualities. This root is nearly inodorous; its taste slightly bitter, sweetish, sub-astringent, and mucilaginous; as it contains no volatile ingredient, it may be given in decoction, but on account of its astringency, it must not be conjoined with a chalybeate. Chemical Composition. According to M. Morin, the Male Fern root owes its anthelmintic property to a fatty substance, capable of being saponified; of a nauseous odour quite like that of the root; of a very disagreeable taste, heavier than water, and distilling with water, and when burnt, giving a dense aromatic smoke. The root, moreover, contains gallic and acetic acids; uncrystallizable sugar; tannin; starch; a gelatinous matter insoluble in water and alcohol; lignine; and various salts. M. Morin considers the fatty matter as formed of a fixed and a volatile oil, but farther experiments are required to make the characteristic principle of this root better understood. (Ann. de Chim. xxvi. 219.) Dose, as an anthelmintic,^[511] ʒj to 377ʒiij, followed by a cathartic; its use however is superseded by more powerful and certain vermifuges. The root is sometimes boiled in ale to flavour it.

GALBANI GUMMI RESINA. L.E.D.

Galbanum.

Qualities. Form, variegated masses, of a yellowish brown colour; Odour, fetid; Taste, bitter and acrid. Chemical Composition. It is one of those vegetable products to which the name of gum-resin has been given, see Elemi. The latest analysis of galbanum by M. Meisner, affords the following results, Resin 65·8; Gum 22·6; Cerasin 1·8; Malic acid 0·2; Volatile oil 3·4; Vegetable Debris 2·8; loss 3·4. Solubility. Water, wine, and vinegar, by trituration, take up one-fourth of its weight, and form a milky mixture, which deposits its charge by rest; a permanent suspension, however, may be effected by the intermedium of egg or of gum arabic, for which purpose the galbanum will require half its weight of gum. Alcohol takes up one-fifth of its weight, and a golden yellow tincture results, which has the sensible qualities of the galbanum, and becomes milky on the addition of water, but no precipitate falls. A mixture of two parts of rectified spirit and one of water, will dissolve all but the impurities. By distillation, galbanum yields half its weight of volatile oil, which at first has a blue colour. Med. Uses. It is antispasmodic, expectorant, and deobstruent, and in a medical classification, might be placed between ammonia and assafœtida. Forms of Exhibition. No form is preferable to that of pill. Officinal. Prep. Pil. Galbani comp. L. Pil. Assafœtid. comp. E. (B) Pil. Myrrh. co. D. Tinct. Galb. D. Empl. Galb. D. Emplast. Galb. co. L. Emplast. Assafœtid. E. (B) Emplast. Gummos. E.

GALLÆ. L.E.D.

(Cynips Quercus folli Nidus.) Gall Nuts.

Qualities. Form, excrescences, nearly round and of different magnitudes, smooth on the surface, but studded with tuberosities; they are heavy, brittle, and break with a flinty fracture. Odour, none; Taste, bitter and very astringent. Solubility. The whole of their soluble matter is taken up by forty times their weight of boiling water. Alcohol, by digestion, dissolves .7, and æther .5 of their substance. The watery infusion possesses all the properties of the gall-nut, and reddens vegetable blues. Chemical Composition. Is at present involved in some obscurity; it contains tannin, gallic acid, a concrete volatile oil, and perhaps 378extractive and gum. M. Braconnot has also lately discovered in the gall-nut a new acid, which he calls Ellagic acid, from the word galle reversed, a nomenclature which it must be confessed is at least free from the objections urged against that which is founded upon chemical composition. (See Annales de Chimie, vol. ix. p. 187, new series; also Children’s Essay on Chemical Analysis, p. 276.) Incompatible Substances. The infusion and tincture of galls possess habitudes with which it is very important for the medical practitioner to be acquainted, not only for the purpose of directing their exhibition with success, but because the elements which impart to them their characteristic traits, viz. Gallic Acid and Tannin,^[512] are very widely diffused through the products of the vegetable kingdom, and will be found to be constantly active in their chemical, medicinal, and pharmaceutical relations. Metallic salts, especially those of iron, produce precipitates with infusion of galls, composed of tannin, gallic acid, and the metallic oxide; of these compounds the tanno-gallate of iron is the most striking, being of a black colour; those of sub-acetate and acetate of lead are greyish; tartarized antimony produces a yellowish; sulphate of copper a brown; sulphate of zinc reddish black; nitrate of silver, a deep olive; and nitrate of mercury, a bright yellow precipitate; the oxy-muriate of mercury produces only an opacity. Sulphuric acid throws down a yellowish curdy precipitate, muriatic, a flaky and white one, and nitric acid merely modifies the colour of the infusion, although it destroys its astringency; the solution of ammonia occasions no precipitate but renders the colour deeper, the carbonate however throws down a precipitate; the carbonates of the fixed alkalies produce a yellowish flaky, and lime water a copious green precipitate. The tannin in the infusion of galls is precipitated by a solution of isinglass or of any other animal jelly, by that of starch, and by many metallic oxides. Medicinal Uses. Galls are most powerfully astringent. The native practitioners of India not only administer them as astringents in dysentery, but as tonics in cases of intermittent fever. Forms of Exhibition. In that of powder; and in combination with other astringents (Form. 51,) or with aromatics and bitters. As a local remedy the gall-nut enters into gargles and injections; for blind piles, an ointment composed of 2½ parts of finely powdered galls, and a small portion of opium, with three parts of simple ointment as an excipient, offers a very valuable resource. (Form. 55.) In some cases of hemorrhoids, prolapsus ani, and fluor albus, the application may be made in the form of a fomentation, for which purpose two drachms of bruised galls should be macerated for an hour in a pint of boiling water, which, when cold, may be used in the usual manner. Dose, for internal exhibition, grs. x–℈ij, or more. Officinal Prep. Tinct. Gallarum. E.D. Observation. Those which are small, protuberant, bluish, and heavy, are the best, being such as have been collected before the larvæ within them had changed to the state of fly, and eaten their way out; a white, or a red hue indicates an inferior quality, and are those from which the insect has escaped. Aleppo galls are the most valuable, as being the most astringent.

379GENTIANÆ RADIX. L.E.D.

(Gentiana Lutea, Radix.) Gentian Root.

Qualities. Form, wrinkled pieces of various length and thickness; Odour, not particular; Taste, intensely bitter, but not nauseous. Chemical Composition, resin, a small portion of oil, bitter extractive, and a proportion of tannin; it contains also mucilage, in consequence of which the infusion frequently becomes ropy. Since the last edition of this work, the continental chemists have announced the existence of an alkaline principle, which they call Gentia or Gentiania, and which is said to concentrate within itself all the virtues of the Gentian root; it does not appear to be in the least poisonous; M. Majendie has injected it into the veins without any obvious effects, and has himself swallowed two grains without experiencing any sensation but that of extreme bitterness, followed by gentle warmth in the region of the stomach.^[513] The root, moreover, contains saccharine matter, for when fermented with water, it yields a spirit which is extensively used by the Swiss. Solubility. The virtues of this root are extracted by water and alcohol; proof spirit is perhaps its most perfect menstruum. See Infus. Gentian. comp. Med. Uses. It is tonic and stomachic, and its use for such purposes is of ancient date;^[514] in dyspepsia, hysteria, and in all cases where a vegetable bitter is indicated, it will be found a serviceable remedy. Dose, in substance, from grs. x to ʒj. Officinal Preparations. Extract: Gentian. L.E.D. Infusum Gentianæ comp. L.E.D. Tinct. Gentian. comp. L.E.D.^[515] Vinum Gentianæ compositum. E.

GERANIUM MACULATUM.

(Spotted Geranium.)

Radix.

[This plant is very common in the United States, and is usually found in the vicinity of moist, woody situations. From the analysis of Bigelow, it appears to contain a very large proportion of tannin. It is accordingly powerfully astringent, and has been used with advantage in diarrhœa, 380chronic, dysentery and cholera infantum. In powder the dose of the Geranium is from 20 to 30 grs.—in extract, 10 grs.—in tincture from ʒj to ʒij—and in decoction from ℥j to ℥ij.]

GLYCYRRHIZÆ RADIX. L.E.D..nf c

(Glycyrrhiza Glabra.)

Liquorice Root. Stick Liquorice.

Qualities. Taste, sweet and mucilaginous. Chemical Composition. Gum, with a peculiar modication of saccharine matter (Glycion), or sugar in its purest form, for it is not fermentable; on which account it is added to beer for the purpose of imparting a sweet taste, and at the same time enabling it to keep better. Solubility. Water extracts both its principles, but by long coction it becomes bitter; alcohol extracts only its saccharine matter. Med. Uses. It is principally employed as a demulcent in combination with other mucilaginous vegetables; the root will yield nearly half its weight of extract. Liquorice covers the taste of some unpalatable medicines more effectually than any other substance, and it has long enjoyed the reputation of assuaging thirst, whence the Greeks distinguished this root by the term Adipson; and, perhaps, the English word Liquorice may be derived from the same belief. Officinal Prep. Decoct: Sarsaparill: comp. L.D. (O) Infus: Lini, L. (B) Extract: Glycyrrhizæ. L.E.D. Confectio Sennæ^[516] L.E. (O) Adulterations. The powdered root is generally sophisticated with flour, and sometimes with powdered guaiacum; the fraud may be detected by its colour being a fine pale, instead of a brownish yellow, and by its reduced or foreign flavour.

GRANATI CORTEX. L.E.D.

Punica Granatum. Pomorum Cortex.

Pomegranate Bark.

What has been said respecting the Gall-nut, applies with equal truth to this substance. The efficacy of the bark of the root of the pomegranate, says Dr. Ainslie (Mat. Med. of Hindostan), as a remedy for the tape worm is now well established in India; it is given in decoction, prepared with two ounces of the fresh bark, boiled in a pint and a half of water until only three quarters of a pint remain.

381GUAIACI RESINA ET LIGNUM. L.E.D.

(Guaiacum Officinale).

The Resin and Wood of Guaiacum.

A. The Wood.

Qualities. This wood is heavier than water, and emits when heated an aromatic odour; Taste, bitterish and sub-acrid; to extract its virtues long decoction is required. It has enjoyed great reputation as a specific in the venereal disease; it was imported into Europe in 1517, and gained immediate celebrity from curing the celebrated Van Hutten: long before this period, however, it was used by the natives of St. Domingo. Boerhaave, so late as the eighteenth century, maintained its specific powers. It seems probable that the discipline which always accompanied its exhibition, such as sweating, abstinence, and purgation, might be the means, in the warmer climates, of effecting cures which were attributed to the guaiacum. Officinal Preparations. Decoct: Guaiaci comp: E. Decoct: Sarsaparill: comp: L.D.

B. The Guaiac, or Resin.

Qualities. Form; it has the aspect of a gum resin; Colour, greenish brown; it is easily pulverized, and the powder, which is at first grey, becomes green on exposure to air and light, which appears to depend upon the absorption of oxygen: when heated, it loses its colour; it melts by heat; and has a sp. grav: of 1·2289. Solubility. Water dissolves out of it about 9 per cent. of extractive matter; alcohol 95, and æther 40 parts in a hundred. The alkaline solutions and their carbonates dissolve it readily; Sulphuric acid dissolves it with scarcely any effervescence, and affords a solution of a rich claret colour; Nitric acid dissolves it with a copious extrication of nitrous fumes; Muriatic acid dissolves a small portion only; but in all these cases the guaiacum is decomposed; the acids are therefore incompatible with it. Chemical Composition. The experiments of Mr. Hatchett demonstrate that it is a substance sui generis, and not a resin, or gum-resin. Med. Uses. Stimulant, diaphoretic,^[517] and in large doses, purgative. Forms of Exhibition. In that of bolus; or diffused in water, by means of one half of its own weight of gum arabic. Dose, gr. x. to ʒss. Officinal Prep: Mist: Guaiac: L. Tinct. Guaiac. 382L.E.D. Tinct. Guaiac. Ammoniat. L.E.D. Pulv. Aloes com. L.D. (O.M.) Adulterations. Common resin may be detected by the turpentine emitted when the guaiac is thrown upon hot coals; Manchinal gum, by adding to the tincture a few drops of sweet spirit of nitre, and diluting with water; the guaiac is thus precipitated, but the adulteration floats in white striæ.

HÆMATOXYLI LIGNUM. L.E.D.

(Hæmatoxylon Campechianum). Logwood.

Qualities. The wood is hard, compact, and heavy. Odour, none; Taste, sweet, and astringent; Colour, deep red. Chemical Composition. The colouring matter of this wood has been very recently submitted to a rigid examination; and the name of Hematin has been given to it; it affords small brilliant crystals of a reddish white colour, and slightly astringent, bitter, and acrid flavour; sulphuretted hydrogen passed through its solution in water, gives it a yellow colour, which disappears in a few days. Gelatine throws it down in reddish flakes. The habitudes of Logwood are curious with respect to mutability of colour. The recent infusion, made with distilled water, is yellow, but that with common water has a reddish purple colour, which is deepened by the alkalies, and changed to yellow by the acids; various salts precipitate it; acetate of lead; alum; the sulphates of copper and iron; tartarized antimony; and sulphuric, muriatic, nitric, and acetic acids, are on this account incompatible with it. Med. Uses. It is supposed to be astringent, and is therefore given in protracted diarrhœas, and in the latter stage of dysentery. Officinal Prep. Extract. Hæmatoxyli. L.

HELLEBORI FŒTIDI FOLIA L.

(Helleborus Fœtidus). Helleboraster. D.

The Leaves of Fœtid Hellebore.

As this plant is merely retained in the list of materia medica on account of its anthelmintic properties, it might be well dispensed with, since we possess many others which are much more safe, as well as more efficacious.

HELLEBORI NIGRI RADIX. L.E.D.

The Root of Black Hellebore. Melampodium.^[518]

Christmas Rose.

Qualities. The fibres of the root are the parts employed; they are about the thickness of a straw, corrugated, externally of a deep dark colour, hence the epithet black; internally white, or of a yellowish hue. 383Odour, unpleasant; Taste, bitter and acrid. Chemical Composition. An analysis of this root has lately been effected by M. M. Feneulle and Capron, from which it appears that its active principle, unlike that of the White Hellebore (Veratrum) is not an alkali; the following substances enter into its composition, viz. 1. A Volatile Oil.—2. A Fatty matter.—3. A Resin.—4. Wax.—5. A Volatile Acid.—6. A bitter principle.—7. Mucus.—8. Alumina.—9. Gallate of Potass.—10. Acidulous Gallate of Lime.—11. A Salt, with an Ammoniacal base. Solubility. Both water and alcohol extract its virtues, but the spirituous solution is the most active; long coction diminishes its powers, hence the watery extract acts more mildly than the root. Medicinal Uses. This is one of the most ancient articles of the materia medica. Ctesias, who lived in the time of Plato, and anterior to Hippocrates, speaks of it as a medicine of important virtues. By the Greek and Roman physicians it was highly esteemed as a remedy in Mania (see p. 8.) The extraordinary cures performed at the island of Anticyrus, famous for its Hellebore, are celebrated by the poets and historians of antiquity. It is a drastic cathartic, and may prove therefore emmenagogue, and hydragogue, but in this country, its reputation has been destroyed by the decided manner in which Dr. Cullen reprobated its use. Forms of Exhibition. It is seldom given in substance, but in the form of tincture or extract; or in that of decoction, made with two drachms of the root to a pint of water. Dose of the powdered root, grs. x to ℈j; of the decoction, f℥j. Officinal Preparations. Tinct. Hellebori Nigri. L.E.D. Extractum Hellebori Nigri. E.D. Adulterations. The roots of the poisonous aconites are often fraudulently substituted; this is easily discovered, for the aconite is lighter coloured than the palest specimens of black hellebore; it is safe therefore to choose the darkest.

HORDEI SEMINA. L.E.D.

(Hordeum Distichon. Semina, tunicis nudata.)

Hordeum Perlatum. Pearl Barley.

Barley is formed into Pearl Barley, by the removal of its husk or cuticle,^[519] and afterwards by being rounded and polished in a mill. These well known granules consist chiefly of fecula, with portions of mucilage, gluten, and sugar, which water extracts by decoction, but the solution soon passes into the acetous fermentation; the bran of barley contains an acrid resin, and it is to get rid of such an ingredient that it is deprived of its cuticle. Officinal Preparations. Decoct. Hordei. L.E.D. Decoct. Hordei. comp. L.D.

384HUMULI STROBILI. L.E.

(Humulus Lupulus. Stroboli Siccati.)

Qualities. Odour, fragrant, and sub-narcotic. Taste, bitter, astringent, and aromatic. Chemical Composition. Tannin, 5 grs.; Extractive, 10 grs.; Bitter principle, 11 grs.; Wax, 12 grs.; Resin, 36 grs.; Lignin, 46 grs. The fact, with respect to the residence of the properties of the hop in the yellow grains scattered over its scales, has been since confirmed by the observations of M. Payen and A. Chevalier, who have moreover detected a volatile oil in the Lupulin, amounting to 2 per cent.; its proportion, however, appears to vary in the Hop of different countries; the French hop, for instance, has been found to contain more than the Belgic, but less than the English; Hops, moreover, soon after having been picked, yield, cæteris paribus, more oil and less resin than the old; a circumstance which induced M. M. Payen and Chevalier to suspect that the oil is capable of being resinified. (Journal de Pharmacie, Juin 1822.) This oil is similar in odour to the hop, but much more penetrating, narcotic, and very acrid in the throat.

Solubility. Boiling water, alcohol, and æther, extract their virtues; but their aromatic flavour is destroyed by decoction; like most vegetable bitters, the cold is more grateful than the warm infusion; its colour is deepened by alkalies, and rendered turbid by the mineral acids; metallic salts also produce decomposition. Medicinal Uses. Hops have been said to be tonic, narcotic, and diuretic; they have been recommended in the cure of rheumatism; and, like many articles in the materia medica which have received the sanction of respectable practitioners, they have been extolled far beyond their merit. They undoubtedly possess the advantages of a pleasant bitter combined with a feeble narcotic; the late Mr. Freake was very sanguine as to their powers, and at his request I made a series of experiments at the Westminster Hospital, but I confess that their results have not established my confidence in their efficacy. Officinal Preparations. Extract. Humili. L. Tinct. Humili. L. Their use as a preservative of beer is well known, and the philosophy of their agency is fully described in the first part of this work, (page 168); it is equally notorious, that various vegetable substances are daily substituted for them, such as Quassia^[520] and Wormwood, both of which are inferior to the Menyanthes Trifoliata, or Marsh Trefoil. The people of Jersey are said to use the wood-sage, Teucrium Scorodonia; it imparts however a very high colour to the beer. During the first four years that the Cape of Good Hope was in the possession of the British, more than 300,000 pounds of Aloes were imported into England; how could such a quantity be consumed? except, as Mr. Barrow states, by the London Porter brewers; it must however be allowed that a considerable quantity of this article is used by the Varnish makers.

385HYDRARGYRUM.^[521] L.D. Hydrarcyrus. E.

Olim, Argentum vivum. Mercury, or Quicksilver.

Mercury, in its metallic state, is never applied to any medical use,^[522] except in visceral obstruction, in hopes of forcing a passage by its gravity; but under various forms of preparation, it affords a series of very active remedies. Adulterations. With the exception of Peruvian Bark, there is perhaps no active article in the materia medica more shamefully adulterated; its impurity is at once indicated by its dull aspect; by its tarnishing, and becoming covered with a grey film; by its diminished mobility, in consequence of which its globules are unable to retain the spherical form, and therefore tail, as it is technically expressed. Lead is discovered by dissolving it in nitric acid, and adding to the solution water impregnated with sulphuretted hydrogen, when, if lead be present, a dark brown precipitate will ensue. Bismuth, by pouring the nitric solution into distilled water, when it will appear as a white precipitate. Zinc, by exposing the mercury to heat. Tin is detected by a dilute solution of nitro-muriate of gold, which throws down a purple precipitate. The presence of lead in mercury is a most dangerous circumstance; I have once witnessed a case of cholica pictonum in consequence of it. The usual mode of purifying quicksilver, by pressing it through chamois leather, will not separate the lead, if it be, as is generally the case, in combination with bismuth; for the manner in which the adulteration is effected, is by melting with a gentle heat these two metals, and adding the alloy to the mercury; and although this alloy should exceed one-fourth of the whole bulk, it will pass, together with the mercury, through chamois leather. On standing, the bismuth will be thrown upon the surface, in the form of a dark powder, but the lead will remain in solution. The greatest part of the mercury of commerce comes from Istria and Friuli, and from the Palatinate, and as it passes through the hands of the Dutch, we must expect to receive it in a state of alloy. On a superficial examination, it ought not, when shaken with water, to impart to it any colour; when agitated or digested with vinegar, it should not communicate a sweetish taste; and when exposed in an iron spoon to heat, it ought to evaporate entirely. The French are so well aware of the mischievous extent to which this metal is falsified, that in their late Codex they direct the reduction of the red oxyd in order to obtain it; the process however is too expensive for general adoption. The Italian Jews purify quicksilver for their barometers, by digesting it in dilute sulphuric acid, which is by no means an improper process. The mode directed 386for the purification of mercury by the London College, (Hydrargyrum Purificatum) is unable to separate it completely from its more deleterious contaminations. It is a general opinion in Germany, that mercury, boiled in water, will impart to it an anthelmintic virtue;^[523] this, if it happens, can only depend upon the impurities of the mercury; but large draughts of cold water are in themselves anthelmintic. Although metallic mercury in its fluid form exerts no effect upon the animal system, it, nevertheless, in a state of vapour, manifests considerable powers; and it is necessary for the practitioner to be informed that it assumes this condition at the ordinary temperature of the atmosphere. I have stated several experiments in proof of this fact in my work on Medical Jurisprudence, Art. “Aerial Poisons,” to which the reader may refer.

HYDRARGYRUM PRÆCIPITATUM ALBUM. L.

Sub-murias Hydrargyri Ammoniatum. D.

White Precipitate.

Qualities. Form, an impalpable powder of a snowy whiteness; Odour and Taste, none. Chemical Composition. It is a triple compound of oxide of mercury 81, muriatic acid 16, ammonia 3 parts. Solubility. It is insoluble in water, and in alcohol; when triturated with lime water it does not become black. It is now only used in combination with lard as an ointment; formerly it was administered internally, and Boerhaave strongly recommends it as a safe and mild mercurial, and as seldom, if ever, exciting copious salivation. Officinal Prep. Unguent. Hydrarg. præcipitati albi. L.D.

HYDRARGYRUM CUM CRETA. L.D.

Mercury with Chalk.

This is mercury slightly oxydized by trituration, and mixed with chalk. Grs. iij contain about one grain of mercury. Dose, grs. v to ʒss. It is a mild and excellent mercurial, and has been known to cure syphilitic affections, when the constitution had proved rebellious to every other form of preparation. Dr. George Fordyce committed a great error, when he denied to this compound any mercurial efficacy. The peculiar mildness of this preparation has been very justly attributed to the effects of the carbonate of lime, in neutralizing acid matter in the primæ viæ. In Mesenteric affections I have employed it with much advantage; in certain forms of Dysentery it is also a very valuable medicine.

387HYDRARGYRI NITRICO-OXYDUM. L.

Oxydum Hydrargyri rubrum per acidum Nitricum. E.

Oxydum Hydrargyri Nitricum. D.

Nitric Oxyd of Mercury—Red Precipitate.

Qualities. Form, small scales of a bright red colour; Taste, acrid and corrosive. Chemical Composition. It is strictly speaking a sub-nitrate of mercury, for if it be boiled for a short time with six times its weight of water, the liquor when filtered yields a precipitate with ammonia. Solubility. It is slightly soluble in water, but extensively in nitric acid, without any effervescence. Uses. It is used only externally, as an escharotic. Officinal Prep. Unguent. Hydrargyri Nitrico-oxyd. L.E.D. Adulterations. Red Lead may be detected by digesting it in acetic acid, and adding sulphuret of ammonia, which will produce a dark-coloured precipitate: it should be totally volatilized by heat.

HYDRARGYRI OXYDUM CINEREUM. L.E.

Pulvis Hydrargyri Cinereus. D.

Grey Oxyd of Mercury.

Qualities. Form, an impalpable grey coloured powder, which becomes paler on exposure to air and light. Odour and taste, none. Chem. Composition. When properly prepared it is protoxide of mercury; but, as frequently found in the shops, it contains a mixture of the triple salt consisting of oxide of mercury, ammonia, and nitric acid. It is rarely used; although Dr. Saunders suggested it as a succedaneum for Plenck’s remedy, and Mr. Abernethy considers it preferable to the red Sulphuret for mercurial fumigation, on account of its not yielding any suffocating vapour. Officinal Prep. Unguent. Oxyd. Hydrarg. ciner. E.

HYDRARGYRI OXYDUM RUBRUM. L.

Oxydum Hydrargyri. D.

Red Oxyd of Mercury.

The Precipitate per se of the older Chemists.

Qualities. Form, minute crystalline scales, of a deep red colour, inodorous, but acrid and caustic; it is soluble in several of the acids without decomposition; it is also slightly soluble in water; from which solution it is precipitated by ammonia. Uses. It is very active as a mercurial, and has been a favourite remedy with John Hunter (Form. 141) and other celebrated practitioners; it is however apt to affect the bowels, and is therefore now rarely employed except as an external application. Dose, gr. j. combined with opium gss. Adulterations. It is seldom adulterated, 388as it would be difficult to find a substance suited to that purpose. If well prepared it may be totally volatilized by heat.

HYDRARGYRI OXY-MURIAS. L.

Murias Hydrargyri Corrosivus. E.D.

Oxy-muriate of Mercury.

Corrosive Muriate of Mercury. Corrosive Sublimate.

Qualities. Form, a crystalline mass, composed of very small prismatic crystals, which is easily pulverized, and undergoes a slight alteration by exposure to air, becoming on its surface opaque and pulverulent. Light, however, has no effect upon it, although a different opinion has existed, and it has accordingly been recommended to be kept in black bottles. Odour, none. Taste, very acrid, with a metallic astringency, occasioning a sensation of obstruction in the throat which continues for some time. Sp. gr. 5·1398. When pulverised and thrown upon burning coals, it is immediately volatilized, giving out a thick white smoke of a very pungent smell, which irritates the mucous membranes extremely, and is highly dangerous to those who inhale it. Chemical Composition. According to the latest views, it is a Bi-chloride of mercury, consisting of one proportional of mercury, to two proportionals of chlorine. In the French codex, it is termed “Deuto-Chloruretum Hydrargyri.” Solubility. It is soluble in eleven parts of cold, and in three of boiling water, and in half its weight of alcohol; it is also very soluble in æther; indeed this latter liquid has the curious property of abstracting it from its solution in water, when agitated with it. Its solubility in water is greatly increased by the addition of a few drops of rectified spirit, or of muriatic acid. In a solution of muriate of ammonia it is seventeen times more soluble than in water, no decomposition however arises; it is therefore probable that a triple salt is formed; it is also soluble in the sulphuric, nitric, and muriatic acids, and may be obtained again unaltered, by simply evaporating the solutions. Dr. Davy, in his late researches upon corrosive sublimate states that with muriatic acid, common salt, and some other muriates, it forms definite compounds remarkable for their solubility. Its watery solution is said to change vegetable blues to green, but this is an optical fallacy, (see page 306.) On exposure to light this solution slowly undergoes decomposition; but Dr. Davy has shewn that corrosive sublimate remains unaltered when exposed in solution in media having a strong affinity for it, as in alcohol, æther, muriatic acid, &c. and that decomposition only takes place under circumstances of complicated affinities, as in the instance of Liquor Hydrargyri Oxymuriatis, and in that of the aqueous solution; in which cases Calomel and Muriatic acid appear to be formed, and oxygen to be evolved. Incompatible Substances. The carbonates of the fixed alkalies precipitate it of a yellow hue, but the precipitates are not pure oxides; ammonia forms with it a white triple compound. Lime water decomposes it more perfectly than any alkaline body, occasioning a precipitate of a deep yellow colour,^[524] which is a per-oxyd of mercury containing 389a little muriatic acid; this result forms a useful lotion to ill conditioned ulcers, and has been long known under the title of Aqua Phagadenica; f℥j of lime water should be employed for the decomposition of two grains of the salt. Tartarized antimony, nitrate of silver, acetate of lead, sulphur, sulphuret of potass, and soaps, decompose it. Iron, lead, copper, bismuth, and zinc, in their metallic state, also decompose it, producing precipitates which consist of an amalgam of the metal employed, except in those cases where the metal in question refuses to amalgamate with mercury, when this latter metal appears as a metallic dew, composed of very minute globules, with calomel; hence mortars of glass or earthenware should be used for dispensing this article; when triturated with olive oil, the oil becomes white, and when boiled with it, calomel is precipitated; the same happens if sugar be substituted for oil. The volatile oils reduce it. When Oil of Turpentine was used, some traces of artificial camphor was discovered by Dr. Davy, and when the oils of Cloves and Peppermint, a purple compound distilled over, consisting of the oil employed and muriatic acid. The following vegetable infusions produce precipitates, viz. the infusions and decoctions of chamomile, horse-radish root, calumba root, catechu, cinchona, rhubarb, senna, simarouba, oak bark, tea and almond emulsion. Swediaur observes, that “many authors have recommended sublimate combined with bark, but that a reciprocal decomposition is thus produced, by which the energies of both remedies are alike annulled;” to this ignorance, however, he thinks that many patients have been indebted for their lives; for, says he, “I see every day examples of weak and very delicate persons of both sexes, to whom ignorant practitioners prescribe, and sometimes in very large doses, the corrosive sublimate, with a decoction of bark; certainly without curing the syphilis, but at the same time without occasioning those grave and dangerous symptoms, which that acrid medicine would certainly produce, if given alone, or without that decoction.” We have here presented the reader with the opinion of Swediaur; but it is just to state, that the experience of this country has rather tended to subvert, than to confirm, such a belief. That the corrosive sublimate of mercury is actually decomposed by the vegetable principles of the bark is sufficiently evident, but it would seem that the oxide thus developed, and recombined with vegetable extractive, is a very active mercurial, especially with respect to its alterative powers. The same observation will, to a certain extent, apply to the results of its decomposition by other agents; the fixed alkalies have been found by actual experiment to be incapable of disarming this salt of its virulence, because, as Orfila has stated, the oxide liberated is, in itself, an active poison. Mr. Rose has lately transmitted to me a formula for the preparation of “Alterative Drops,” which he states, from ample experience, to possess very considerable powers as a mercurial, and to excite ptyalism, with a quickness and certainty which characterize but few preparations of the same class. The principal ingredients are an alcoholic solution of corrosive sublimate and a vinous solution of tartarized antimony. It is scarcely necessary to observe that upon admixture a mutual decomposition takes place; the peroxide of mercury is precipitated by the alkaline element of the antimonial compound, whilst this latter salt, having its affinities thus overthrown, parts with the protoxide of antimony; so that the preparation holds a considerable quantity of insoluble matter in suspension, and which is to be carefully incorporated with the liquid by shaking the phial, whenever the drops are administered. Now there can be but 390little doubt but that the activity of this preparation is owing to the peroxide of mercury, thus diffused in a state of minute division, while at the same time the antimonial protoxide very probably disposes the stomach and system to be more readily influenced by it, for reasons which have been fully discussed in the first part of this work, p. 152. Med. Uses. It is one of the most acrid and active of all metallic preparations; in well directed doses, however, it is frequently of service in secondary syphilis, and in cases of anomalous disease, when it would be improper to administer the other forms of mercury.^[525] In obstinate cutaneous diseases its administration 391in small doses is often very serviceable; I have, however, seen extreme emaciation and hectic fever produced by its too long continued exhibition, although ptyalism was never occasioned. Its application also as a lotion to leprous affections, in the proportion of about one grain to a fluid-ounce and a half of some liquid vehicle, I have frequently seen highly beneficial; in directing the use of so acrid a lotion, we should caution the patient not to touch his eyes until his hands have been washed; in consequence of a neglect of this kind I have seen a very severe ophthalmia produced. The practitioner should also remember that the system may become affected by such external applications; a case stands recorded in which a girl of five years old became salivated, and died, in consequence of an application made to the head for the cure of Tinea, which consisted of Pomatum rubbed up with a few grains of this salt. Its internal exhibition should be accompanied with mucilaginous drinks; when an overdose has been taken, the white of egg, diluted with water, is the best antidote, for Orfila has found that albumen decomposes it, reducing it to the state of mild muriate, whilst the compound which it forms with it is inert. Many examples are recorded of the success of this practice. In the Transactions of the King and Queen’s College of Physicians in Ireland, an interesting case of this kind is related by Dr. Lendrick; it is, however, at the same time but justice to state, that there are instances also of the failure of this antidote. In the 41st volume of the London Medical and Physical Journal, p. 204, the reader will find the case of a girl, who was poisoned by a drachm of Sublimate, and who, notwithstanding the copious ingestion of albumen, died in ninety hours. More recently vegetable gluten, as existing in wheat-flower, is said to answer as well as albumen; for the administration of which all that is required is to give wheat-flower and water. Dose, gr. 1/8 to ½, see Liquor Hydrargyri Oxymuriatis, and Form. 142. Adulterations. It ought to be volatilized by heat; it is frequently met with in commerce contaminated with muriate of iron, sometimes with arsenic; the presence of calomel is at once discovered from its insolubility. Tests of its Presence. If any powder be suspected to contain this salt, expose it to heat in a coated tube, as directed in the treatment of arsenic, but without any carbonaceous admixture, when corrosive sublimate, if present, will rise and line the interior surface with a shining white crust. This crust is then to be dissolved in distilled water, and assayed by the following tests; 1st, lime water will produce, if the suspected solution contains this salt, a precipitate of an orange yellow colour. 2d, a single drop of a dilute solution of sub-carbonate of potass will at first produce a white precipitate, but on a still farther addition of the test, an orange-coloured sediment will be formed. 3rd, sulphuretted water will throw down a dark coloured precipitate, which when dried and strongly heated may be volatilized without any alliaceous odour. 4th, ammonia produces a white precipitate, which is an insoluble triple salt, composed of muriatic acid, ammonia, and oxide of mercury, which, on being heated, grows yellow; it passes afterwards to a red, and gives out ammoniacal gas, nitrogen, calomel, and metallic mercury. In this operation the oxide is supposed to be decomposed by the hydrogen which results from a 392portion of the ammonia. 5th, Nitrate of tin, according to Dr. Bostock, is capable of detecting the three-millionth part of a grain; a single drop will occasion an immediate and copious dark-brown precipitate. All the above precipitates, if rubbed on a bright plate of copper, will render its surface very white. Where the salt is mixed with various coloured liquids, we must proceed as directed under the head of Arsenic. A very ingenious application of galvanic electricity has been also proposed by Mr. Silvester, for the detection of corrosive sublimate, which will exhibit the mercury in a metallic state. A piece of zinc or iron wire about three inches in length, is to be twice bent at right angles, so as to resemble the Greek letter Π, the two legs of this figure should be distant about the diameter of a common gold wedding ring from each other, and the two ends of the bent wire must afterwards be tied to a ring of this description. Let a plate of glass, not less than three inches square, be laid as nearly horizontal as possible, and on one side drop some sulphuric acid, diluted with about six times its weight of water, till it spreads to the size of a halfpenny. At a little distance from this, towards the other side, next drop some of the solution supposed to contain corrosive sublimate, till the edges of the two liquids become joined; and let the wire and ring, prepared as above, be laid in such a way that the wire may touch the acid, while the gold ring is in contact with the suspected liquid. If the minutest quantity of corrosive sublimate be present, the ring in a few minutes will be covered with mercury on the part which touched the fluid. This experiment may be beautifully simplified in the following manner; drop a small quantity of solution containing corrosive sublimate on a piece of gold, and bring into contact a key, or some piece of iron, so as to form a galvanic circuit, when the gold will be immediately whitened. A solution of nitrate of silver will, under similar circumstances, occasion on the gold a white precipitate, but as no amalgamation takes place, it is readily wiped off, and cannot possibly occasion any fallacy.^[526]

Certain metals likewise decompose solutions of this salt, by virtue of superior affinity; in those cases where the precipitating metal is capable of forming a direct union with Mercury, we shall find the precipitates to consist of an amalgam of the metal employed; where no such combination takes place, the mercury will be frequently seen standing on the surface as a metallic dew. This is particularly striking where iron or steel has been employed; these metals are also at the same time blackened by it.

Brugnatelli^[527] has proposed the following method of distinguishing corrosive sublimate from arsenic—Take a quantity of fresh wheat starch, mix with water, and add a sufficient quantity of iodine to give the liquid a blue colour; if corrosive sublimate or arsenic be added to this liquor, the colour is alike destroyed and it becomes reddish, but if the change has been effected by the latter substance, a few drops of sulphuric acid will restore the blue colour, but if by the former it is not recoverable by such means.^[528]

393HYDRARGYRI SUB-MURIAS. L.

Sub-murias Hydrargyri sublimatum. D.

Sub-murias Hydrargyri Mitis. E.

vulgo. Calomel.^[529]

This preparation has been known in pharmacy for upwards of two centuries under a variety of fanciful names, such as Draco mitigatus; Aquila alba; Aquila mitigata; Manna metallorum; Panchymagogum minerale; Panchymagogus quercetanus; Sublimatum dulce; Mercurius dulcis sublimatus; Calomelas; and yet there is not a name in this list that is so objectionable as the one at present adopted by our colleges: for whether we adhere to the theory of muriatic acid being the simple body, or accede to the new views of chlorine, the name is equally inappropriate; if we regard it as a compound of muriatic acid and oxyd of mercury, it is not a sub-muriate, but as much a muriate as the corrosive sublimate; the only difference depending upon the degree of oxidizement of the mercury, which is at a minimum in calomel, and at a maximum in sublimate. According to the new views respecting chlorine, calomel must consist of one proportional of chlorine with one proportional of metal, and is therefore a chloride of mercury. (“Proto-chloruretum Hydrargyri.” Codex Med. Paris.)

Qualities. Form. A semi-transparent mass, consisting of short prismatic crystals;^[530] inodorous, insipid, and of an ivory colour, which deepens by exposure to light. Solubility. It is considered as being insoluble, since according to Rouelle, one part requires 1152 of water, at 212° for its solution. Incompatible Substances. Alkalies and lime water decompose it and turn it black, in consequence of precipitating the black oxyd of the metal; it is also decomposed by soaps, sulphurets of potass and antimony; and by iron, lead, and copper; hence it is improper to employ any metallic mortar for dispensing medicines which contain it. There seems to be reason for supposing that this preparation may undergo decomposition in transitu, and that therefore some substances may be chemically, and yet not be medicinally incompatible with it. If calomel be boiled for a few minutes in distilled water to which alcoholized potass has been added, it is completely decomposed, a muriate of potass and black oxyd of mercury being the new products. Calomel is not affected by sulphuric acid in the cold, but, at a boiling temperature, corrosive sublimate, and deuto-sulphate of mercury are formed. Medicinal Uses.^[531] This mercurial preparation 394is more extensively and more usefully employed than almost any other article of the materia medica. It is capable of curing syphilis in every form, provided it does not run off by the bowels; and in obstructions and hepatic affections, it is in well-regulated doses a most valuable remedy; in combination, it probably merits the appellation of Dirigens, more decidedly than any other remedy with which we are acquainted, for when combined with certain diuretics, it is diuretic, (Form. 103, 104) and in diaphoretic arrangements, it is diaphoretic: it moreover imparts force to many of the mild, and moderates the severity of drastic medicines: whenever we wish a strong and permanent impression to be made on the alimentary canal, and through it on the neighbouring viscera or the system generally, Calomel by universal consent is adopted for such a purpose. (Form. 81, 88, 119, 161.) In larger doses it is one of the most efficient purgatives which we possess, especially when in combination with other cathartics: it appears to be particularly eligible in the diseases of children; and it is singular that infants can generally bear larger doses of it than adults. Dose, as an alterative, from gr. ss to j, night and morning; as a purgative, from gr. ij to gr. x, or in some cases even to gr. xv, or ℈j. Forms of Exhibition. That of pill; its insolubility and specific gravity render any other form ineligible. Officinal Preparations. Pil. Hydrargyri submuriat. comp: L. Impurities. Corrosive sublimate may be detected by precipitation being produced, by the carbonate of potass, in a solution made by boiling the suspected sample with a small portion of muriate of ammonia, in distilled water; calomel ought also, when rubbed with a fixed alkali, to become intensely black, and not to exhibit any trace of an orange hue.

Howard’s or Jewel’s Hydro-sublimate. Instead of subliming so as to obtain the calomel in a concrete state, as directed by the Pharmacopœia, the salt in the act of sublimation is exposed to aqueous vapour, and received in water. Being in a state of very minute division, it is lighter than common calomel in the proportion of three to five, and it cannot contain any corrosive sublimate. The French in their late codex have introduced a similar formula, under the title of “Murias Mercurii dulcis mediante aqua subtilissime divisus, juxta Methodum Josiæ Jewel.”

This Patent Calomel of Howard is undoubtedly to be preferred, and appears, in consequence probably of its minute division, to affect the system more readily than that made according to the Pharmacopœias.

Sub-murias Hydrargyri Præcipitatus. E.D. This is produced by precipitating a nitrate of mercury by muriate of soda; the preparation will generally contain a small portion of sub-nitrate, and it is on that account more liable to run off by the bowels in small doses: in other respects it is essentially the same as that procured by sublimation.

395HYDRARGYRI SULPHURETUM RUBRUM. L.

Sulphuretum Hydrargyri rubrum. D. Olim, Hydrargyrus Sulphuretus ruber. P. L. 1817—Cinnabaris^[532] factitia, 1745.

Qualities. Form, a red crystalline cake, inodorous, insipid, and insoluble in water, alcohol, acids, and alkalies, although these bodies decompose it when melted with it; it is also decomposed by nitro-muriatic acid, which unites with the metal, and disengages the sulphur. Chemical Composition. It is a bi-sulphuret of Mercury, i. e. it consists of two proportionals of sulphur and one of mercury. Uses.^[533] It is now only used for the purpose of mercurial fumigation, which is done by inhaling the fumes, produced by throwing ʒss of it on red hot iron; the effect which is generally produced is violent salivation; this however does not depend upon the action of the substance as a sulphuret, but upon its decomposition, and the volatilization of the metallic mercury with a portion of sulphate and sulphureous vapour. Mr. Pearson observes that it is useful in those cases of venereal ulcers in the mouth, throat, and nose, where it is an object to put a sudden stop to the progress of the disease, but that mercury must at the same time be introduced into the constitution, by inunction, just as much as if no fumigations had been made use of. Ulcers and excrescencies about 396the pudendum and anus in women are particularly benefitted by it; and in these cases it is conveniently applied by placing a red hot heater at the bottom of a night-stool pan, and after sprinkling on it a few grains of the sulphuret, placing the patient upon the stool. Adulterations. Red Lead^[534] may be discovered by digesting it in acetic acid, and by adding sulphuret of ammonia, which will produce a black precipitate; or by burning a small portion of the suspected sample on a piece of bread in the candle, when metallic globules will announce its presence; for the oxide of mercury, although revived by this process, will at the same time be volatilized. The bread, by combustion, affords the carbon by which the metallic reduction is effected. Dragon’s Blood, by its giving a colour to alcohol when digested with it; Chalk, by its effervescence, on the addition of an acid. It is known in the arts under the name of Vermillion; and by the following simple expedient its presence may, in very minute quantities, be easily recognised; boil a portion with sulphuric acid in a platina spoon, and lay the sulphate thus produced, in a drop of muriatic acid, on a piece of gold, and bring a piece of metallic tin in contact with both, when the white mercurial stain will be produced.

HYDRARGYRI SULPHURETUM NIGRUM. L.E. Hydrargyrus cum Sulphure. P.L. 1787. Olim, Ethiop’s Mineral.

Qualities. Form, a very black, impalpable, insipid, and inodorous powder. Chemical Composition. It is a Sulphuret of Mercury, i. e. it consists of one proportional of sulphur, and one proportional of mercury; when heated in contact with the air it is converted into a bi-sulphuret. Solubility. It is entirely soluble in a solution of pure potass, from which the acids precipitate it unchanged; it is insoluble in nitric acid. Med. Uses. It is supposed to be alterative, and has been given for such a purpose, in doses from gr. v. to ʒss, but its medicinal virtues are very questionable. Adulterations. It is frequently imperfect, globules of mercury being still discoverable in it by a magnifying glass, or by its communicating a whiteness to a portion of gold upon which it is rubbed; ivory black may be discovered by the residue, after throwing a suspected sample on a red hot iron; it is also sometimes mixed with equal parts of crude antimony.

HYOSCYAMI FOLIA ET SEMINA. L.E.D.

(Hyoscyamus Niger.) Henbane.

Qualities. This plant, when recent, has a strong fetid, and narcotic odour; properties which are nearly lost by exsiccation. Chemical Composition. Resin, mucilage, extractive matter, gallic acid, and some salts; 397an alkaline element (Hyoscyama) is said to constitute its active principle. This principle differs from other vegetable alkalies, in being able to resist a low red heat, without undergoing decomposition. Solubility. Water freely extracts the narcotic powers of this plant, and decoction destroys them; diluted alcohol is the best menstruum. Incompatibles. Precipitates are produced by acetate of lead, nitrate of silver, and sulphate of iron; vegetable acids weaken its narcotic powers. The extract or inspissated juice is the best form in which it can be exhibited; see also the Tincture; its leaves form an anodyne cataplasm, and the smoke from its seeds, when applied by a funnel to a carious tooth, is recommended in severe fits of odontalgia. The root of this plant is poisonous.^[535] In Dr. Molyneux’s appendix to Threlkeld’s “Synopsis Stirpium Hibernicarum” are related several cases of its effects on persons who had eaten them instead of Skirrets. Officinal Prep. Extract: Hyoscyam: Tinct: Hyoscyam: L.E.D.

ICHTHYOCOLLA.

(Acipenser Huso & Ruthenus. The great and small Sturgeon.)

Isinglass. Fish Glue.

The following kinds, imported from St. Petersburg, are found in the market. Short Staple; Long Staple; Book; and Leaf. Picking the Staple, as it is called, is a peculiar art practised by persons in this town, who gain a very good livelihood by it; they engage to return the same weight of isinglass in shreds, as they receive in Staple; this in itself secures very fair profit, for by damping the isinglass in order to pick it, it gains considerable weight; these persons moreover are in the habit of adulterating it with pieces of bladder, and the dried skin of soles; such frauds however are easily detected by their insolubility, for pure isinglass will dissolve entirely, and yield a clear and transparent jelly; a single grain will produce, with an ounce of water, a solution of considerable thickness; it is also soluble in acids and alkalies; and although insoluble in alcohol, yet it is not precipitated by it from its watery solutions, unless when added in a very considerable quantity; it is coagulated by the infusions and decoctions of vegetable astringents; carbonate of potass likewise throws down a precipitate. 100 parts of good isinglass consist of 98 of gelatine, and 2 of the phosphates of soda and lime. Its solutions soon putrefy. Uses. It is now rarely used except as a nutrient; its mechanical application in fining wines and turbid liquors is well known, and its mode of operation is equally obvious, for by forming a skin, or fine network, which gradually precipitates, it acts just like a filtre, with this difference, that in this case the filtre passes through the liquor, instead of the liquor through the filtre.

INFUSA. L.E.D. Infusion.

These are watery solutions of vegetable matter, obtained by maceration, 398either in cold or hot^[536] water without the assistance of ebullition. In selecting and conducting the operation, the following general rules should be observed.

I. Infusion should always be preferred to decoction, where the medicinal virtues of the vegetable substance reside in volatile oil, or in principles which are easily soluble; whereas, if they depend upon resino-mucilaginous particles, decoction is an indispensable operation.

II. The temperature employed must be varied according to the circumstances of each case;^[537] an infusion made in the cold, is in general more grateful, but less active, than one made with heat.

III. The duration of the process must likewise be regulated by the nature of the substances, or the intention of the prescriber; for the infusion will differ according to the time in which the water has been digested on the materials; thus, the aroma of the plant is first taken up, then, in succession, the colouring, astringent, and gummy parts.

Infusions are liable to undergo decompositions by being kept, and therefore, like decoctions, they must be regarded as extemporaneous preparations. Unless the dose of them be otherwise stated, it is generally from f℥j to f℥ij.

I. Simple Infusions.

Infusum Anthemidis. L.E. It is a good stomachic; and when exhibited warm, is well calculated to assist the operation of emetics: (Form. 66): the cold infusion, i. e. made with cold water, is more grateful. Incompatibles. All soluble preparations of iron; nitrate of silver; oxy-muriate of mercury; acetate, and sub-acetate of lead; solutions of isinglass; infusion of yellow cinchona bark. Dose, f℥j-f℥ij.

Infusum Calumbæ. L.E. See Calumbæ Radix. This infusion is more perishable than that of other bitters; in twenty-four hours a copious precipitation takes place in it, and in two days it becomes ropy, and even musty. Form. 155. Dose, f℥i-f℥ij.

Infusum Caryophyllorum. L. f℥j. of this infusion holds in solution the active matter of grs. vj of cloves. Incompatibles. Precipitates are produced by sulphate of iron; sulphate of zinc; acetate of lead; nitrate of silver; tartarized antimony; lime water, and yellow cinchona. Dose, f℥j-f℥ij.

Infusum Cascarillæ. L. It is incompatible with the substances mentioned under Infus. Caryophyll: Form. 33. Dose, f℥j-f℥ij.

399Infusum Cinchonæ. L.E.D. We obtain in this preparation a feeble solution of the active constituents of bark, which will agree with many stomachs that are rebellious to the stronger preparations. Dose, f℥i-f℥iij.

Infusum Cuspariæ. L. This is a judicious form of the bark, possessing its stimulant and tonic properties. Dose, f℥j-f℥ij.

Infusum Digitalis. L.E. This is the best form in which we can administer the foxglove, where our wish is to obtain its diuretic effects as speedily as possible. (Form. 110.) Dose, fʒij to f℥ss, twice a day, see Digitalis. Incompatibles. We shall counteract its effects by endeavouring to obviate its nauseating tendency by brandy and water, &c. Precipitates are produced by sulphate of iron, and the infusion of yellow cinchona, &c.

Infusum Lini Compositum. L.E. A cheap and useful demulcent; alcohol and preparations of lead, are of course incompatible with it; the tinctura ferri muriatis produces a flocculent precipitate.

Infusum Quassiæ. L.E. The proportion of Quassia directed for half a pint of water, is that of ℈j by the London, and ʒss by the Edinburgh College; the former is much too small, for, in order to obtain a saturated infusion, ʒij are required for that quantity of water. Incompatibles. The salts of iron produce no change in it; nor is it affected by any of those substances with which it is likely to come in contact in a medical prescription. It is highly useful in debilities of the stomach and intestinal canal, and in irregular and atonic gout, and it has been observed, that in hysterical atony, to which the female sex is so prone, the Quassia affords more vigour and relief to the system, than the Peruvian Bark, especially when combined with a small portion of sulphate of zinc. To this, as well as the other stomachic infusions, it is usual to add at the time of prescribing them a small quantity of aromatic tincture or spirit. Form. 35; 144. Dose, f℥ss-f℥iss.

Infusum Rhei. L.E. The Edinburgh infusion is stronger than that of London, and is rendered more grateful by the addition of spirit of cinnamon; these infusions, however, when given without any adjuvants, produce but a feeble effect. This is obvious, since ℈j of rhubarb in substance, is at least equivalent in its effects to ʒiss when in infusion. Incompatibles. The stronger acids; the sulphates of iron and zinc; nitrate of silver; tartarized antimony; acetate of lead; oxy-muriate of mercury, and the infusions of cusparia, cinchona, catechu, galls, and some other astringent vegetables; the alkalies deepen the colour, but produce no decomposition. Dose, f℥j-f℥ij.

Infusum Simaroubæ. L. This infusion is inodorous, of a clear straw colour, with a slightly bitter taste. It presents the best mode of exhibiting Simarouba bark. Dose, f℥ij, beyond this it will prove emetic. Incompatibles. Alkaline carbonates and lime water render it milky; and it is precipitated by the following substances; infusions of catechu; galls, and yellow cinchona; oxy-muriate of mercury; nitrate of silver, and acetate of lead. See Simaroubæ Cortex.

Infusum Tabaci. L. It is never used but as an enema, in incarcerated hernia, and in ileus. See Tabaci Folia.

2. Compound Infusions.

Infusum Armoraciæ Compositum. L. In this preparation the stimulant property of the horse-radish is materially aided by the mustard; 400pure alkalies, but not their carbonates, may form extemporaneous additions; for the other incompatibles, see Armoraciæ Radix. Dose, f℥iss. Form. 45.

Infusum Aurantii Compositum. L. A grateful stomachic, having the agreeable compound taste of its several ingredients; it has the merit of sitting easily on the stomach. Dose, f℥j-f℥iss.

Infusum Catechu Compositum. L.E. This infusion is a powerful astringent, rendered grateful by the addition of cinnamon; it will keep for several months, provided the directions of the Edinburgh College be not followed in adding the syrup. In prescribing it, we must remember that it contains a large proportion of tannin. See Catechu. Dose, f℥j-f℥iij.

Infusum Gentianæ Compositum. L. An elegant tonic and stomachic infusion. It affords a good example of the virtues of a natural substance being enhanced by the additions of art, as discussed at page 164, for the bitterness of the gentian is here subdued by the aromatic quality of the lemon and orange peel. Incompatibles. Acetate of lead throws down a copious precipitate from the infusion, and sulphate of iron strikes a brown colour, but no precipitate takes place for several hours.