A CYCLOPÆDIA OF PRACTICAL RECEIPTS, PROCESSES, AND COLLATERAL INFORMATION (continued 30)

Another cement consists of about 73 parts of silver, 21 of tin, and 6 of zinc, amalgamated with quicksilver. An amalgam of copper is said to be sometimes used. But this class of stoppings is altogether disapproved of by other authorities. Pure leaf-gold seems the least objectionable.

11. (Marmoratum.) Finely levigated glass, mixed with tin amalgam.

12. (Poudre Metallique.) The article sold under this name in Paris appears to be an amalgam of silver, mercury, and ammonium, with an excess of mercury, which is pressed out before using it.

13. (Fusible Metal.) Melt together 8 parts of bismuth, 5 of lead, 3 of tin, and 1¹⁄₂ or 1·6 of quicksilver, with as little heat as possible. (Chaudet.)

14. (Non-expensive Metallic Tooth-stopping.) Take 1 part of sulphate of mercury, 1 part of copper in fine powder; rub them well together with a little warm water; when the amalgam is formed wash well, and remove the surplus of mercury by pressing it through chamois.—Pharm. Journ.

Expensive Metallic Tooth-stopping and much preferable. Take pure gold, pure gelatin, 1 part of each; pure silver, 2 parts; melt, and when refrigerated, reduce to a powder by means of a file; wash well and dry. In the moment of using it add sufficient mercury to form a plastic paste.—Pharm. Journ.

Paste for Destroying the Sensibility of the Dental Pulp previous to Stopping. Arsenious acid, 30 gr.; sulphate of morphia, 20 gr.; creasote, q. s. [Unsafe; it is only inserted by way of warning against what may prove an unsuspected cause of mischief.]

Pivots for Artificial Teeth. An alloy of platinum and silver.

Springs for Artificial Teeth. Equal parts of copper, silver, and palladium. (Chaudet.)

For Cachou Aromatisé, and other compounds for sweetening the breath, see Perfumery.

DENTI′TION. See Teething.

DEOB′STRUENT. In medicine, a substance which removes obstructions, and opens the natural passages of the fluids of the body, as the pores, lacteals, and glands. Iodine, mercury, sarsaparilla, and aperients, are deobstruents.

DEO′DORISER. Any substance having the power of absorbing or destroying fetid effluvia. Chlorine, chloride of lime, chloride of zinc, nitrate of lead, sulphate of iron, and freshly-burnt charcoal, are the most effective and convenient deodorisers. Peat charcoal has been highly recommended for deodorising manure, &c., on the large scale. When it is mixed with these substances their fetor is immediately destroyed, and a compost produced, which may be substituted for guano for agricultural purposes. ‘Biedermann’s Centralblatt für Agricultur Chemie’ for June, 1877, contains the results of some experiments undertaken by A. Eckstein on the comparative deodorising values of certain substances. Herr Eckstein found that 1 kilo of copperas dissolved in water destroyed the stench of sulphuretted hydrogen in a privy used daily by at least 100 persons. The action ceased after twelve hours. A solution of aqueous sulphate of copper produced a similar result. When 1 kilo of solid copperas was employed the action lasted for two days. The same result was obtained by using 1 kilo of a mixture compound of copperas, sulphate of copper, and carbonate of lime. Liquid sulphurous acid was found to act very rapidly, rendering the atmosphere difficult to breathe for an hour; its action ceased after twenty-three hours. Crude carbolic acid, which was used to the extent of 30 grams, gave so unpleasant a smell for two days as to render the result impossible to be arrived at. One kilo of copperas enclosed in a bag of parchment paper only began to act after two hours, and kept the place odourless for two days. One kilo of good chloride of lime, placed in a similar bag, did not lose its effect for nine days. With 60 grams of permanganate of soda the action commenced immediately, but the effect was over in twenty-four hours; when enclosed in parchment paper it was efficacious for two days. In Herr Eckstein’s opinion the most powerful deodoriser known is chloride of lime along with sulphuric acid. Powdered gypsum is a good absorber of ammonia, and for this purpose may be sprinkled over the floors of stables, manure heaps, &c. See Disinfectant.

DEOX′IDATION. See Reduction.

DEPIL′ATORY. A cosmetic employed to remove superfluous hairs from the human skin. Depilatories act either mechanically (MECHANICAL DEPILATORIES), or chemically (CHEMICAL DEPILATORIES). To the first class belong adhesive plasters, that, on their removal from the skin, bring away the hair with them. The second class includes all those substances which destroy the hair by their chemical action.

Lime or orpiment, and generally both of them, have formed the leading ingredients in depilatories, both in ancient and modern times. The first acts by its well-known causticity, and also, when an alkali is present, by reducing that also, either wholly or in part, to the caustic state. The action of the orpiment is of a less certain character, and its use is even dangerous when applied to a highly sensitive or an abraded surface. The addition of starch is to render the paste more adhesive and manageable.

In using the following preparations, those which are in the state of powder are mixed up with a little warm water to the consistence of a paste, and applied to the part. Sometimes soap lye is used for this purpose, and some persons spread the pulpy mass on a piece of paper, and apply it like a plaster. In 12 or 15 minutes, and sooner, if much smarting ensues, the whole should be washed off with warm water, and a little cold cream, lip-salve, or spermaceti cerate, applied to the part. The application of the liquid preparations is generally accompanied with gentle friction, care being taken to prevent them extending to the adjacent parts. All the following effect the object satisfactorily, with proper management; but some are much more effective than others. A small wooden or bone knife is the best for mixing them with. They must all be kept in well-stoppered bottles, and no liquid must be added to them until shortly before their application; and then no more should be mixed than is required for immediate use.

Depilatory, Arsen′ical. Orpiment (sulphide of arsenic) forms the principal ingredient in many fashionable depilatories, but its use is not free from danger. The following are well-known preparations:

1. (Colley’s D.) From nitre and sulphur, of each 1 part; orpiment, 3 parts; quicklime, 8 parts; soap lees, 32 parts; boil to the consistence of cream. Very caustic.

2. (Delcroix’s d.; ‘poudre subtile,’) Orpiment, 1 oz.; quicklime, 10 oz.; starch, 14 oz.

3. (Oriental d.; Oriental rusma.)—a. Quicklime, 3 oz.; orpiment, ¹⁄₂ dr.; strong alkaline lye, 1 lb.; boil together in a clean iron vessel until a feather dipped into the liquor loses its flue.

b. From pearlash, 2 oz.; orpiment, 3 dr.; liquor of potassa, ¹⁄₂ pint; boil together as before. One of the most caustic and consequently the most certain of depilatory preparations; but, with the rest of its class, open to the objections of containing orpiment. (See No. 7.)

4. (Paste d.; ‘Pâte épilatoire,’) To No. 1 add of orris root, 3 parts.

5. (Plenck’s d.; ‘Pasta epilatoria,’) Orpiment, 1 part; quicklime and starch, of each 12 parts.

6. (Soap d.; ‘Savon épilatoire,’) Turkish depilatory and soft soap, equal parts. Must not be mixed until about to be applied. (See No. 7.)

7. (Turkish d.; Turkish rusma.) Orpiment, 1 part; quicklime, 9 parts. For use, it is mixed up with soap lees, and a little powdered starch.

Depilatory, Boettger’s. Powdered sulphydrate of sodium, one part; washed chalk, three parts; made into a thick paste with a little water. Let a layer about the thickness of the back of a knife be spread upon the hairy surface. After two or three minutes the stoutest hairs are transformed into a soft mass which may be removed by water. A more prolonged action would attack the skin.

Depilatory, Boudet’s. Prep. Sulphide of sodium (crystallised), 3 parts; quicklime (in fine powder), 10 parts; starch, 10 parts; mix. To be mixed with water, and applied to the skin, and scraped off in 2 or 3 minutes with a wooden knife. Very effective and safe.

Depilatory, Cazenave’s. Syn. Mahon’s d.; Pommade épilatoire de Cazenave, Fr. Prep. Quicklime, 1 part; carbonate of soda, 2 parts; lard, 8 parts; mix. Applied as an ointment.

Depilatory, Chi′nese. Prep. 1. Quicklime, 8 oz.; pearlash (dry) and liver of sulphur, of each 1 oz.; all reduced to a fine powder; mixed, and kept in a close bottle.

2. (Roseate d.) As No. 1., but coloured with a little rose pink or light red.

These preparations are applied in the same manner as Boudet’s Depilatory.

Depilatory, Colley’s. See Depilatory, Arsenical.

Depilatory, Hydrosulphate of Lime. Prep. (Beasley.) Mix quicklime and water to a thick cream, and pass into the mixture 25 or 30 times its volume of sulphuretted hydrogen gas. When the gas ceases to be absorbed, stop the process. The pulpy mass is spread on paper, and applied for 12 or 15 minutes. It is very effective, but has a most disgusting smell. Spolasco’s depilatory is a very similar preparation (see below).

Depilatory, Mechan′ical. Syn. Depilatory plastee. Prep. From pitch and resin, equal parts, melted together and spread on leather. Applied as a plaster.

Depilatory, Rayer’s. Prep. Quicklime, 2 oz.; salt of tartar, 4 oz.; charcoal, ¹⁄₄ oz. Less active than Chinese Depilatory.

Depilatory, Redwood’s. Prep. A strong solution of sulphide of barium, made into a paste with powdered starch, and applied immediately. Mr Redwood says this is “the best and safest depilatory.”

Depilatory, Ro′seate. See Depilatory, Chinese.

Depilatory, Spolasco’s. Prep. Freshly prepared sulphide of calcium and quicklime, equal parts. Almost equal to Redwood’s (above).

DEPOSI′TION (of Metals). See Electro-type.

DERBY CONDITION POWDERS (J. Tobias Simpson, New York). Celebrated as a safe, infallible, and speedy remedy for glanders, coughs, colds, over feeding, worms, mouth disease, and loss of horns or hair, in horses and other valuable domestic animals. Tartar emetic, 2 grammes; black antimony, 20 grammes; sulphur, 10 grammes; nitre, 10 grammes; fenugreek, 40 grammes; juniper berries, 20 grammes. (Schädler.)

DER′BYSHIRE NECK. See Goitre.

DERMASOT (Apotheker Bertschinger, Baden, Switzerland). For profuse perspiration of the feet. Consists of acetate of alumina, 7·5 grammes; distilled water, 120 grammes; butyric ether, 2 drops; rosanilin to colour it slightly. (Weber.)

DESBRIERRE’S CHOCOLATE A LA MAGNESIE. 44 grammes of chocolate paste and 15 grammes of calcined magnesia, made into two tablets. (Reveil.)

DESIC′CANTS. Syn. Desiccan′tia, L. In pharmacology, substances that check secretion and dry sores of abraded surfaces, without acting as styptics, or constringing the fibres of the parts to which they are applied. See Astringents.

DESICCA′TION. Syn. Exsicca′tion. The evaporation or drying off of the aqueous portion of solid bodies. Plants and chemical preparations are deprived of their humidity by exposure to the sun, a current of dry air, an atmosphere rendered artificially dry by sulphuric acid, or by the direct application of heat by means of a water bath, a sand bath, or a common fire. Planks and timber are now seasoned, on the large scale, in this way, by which a condition may be produced, in 2 or 3 days, which on the old system is barely attainable in as many years. “Endeavours were made to enforce the importance and value of the desiccation of woods to the builder, cabinet maker, architect, and civil engineer, so long back as 1843, but without success. Since that period certain persons have availed themselves, commercially, of our ideas and experiments on the subject, without any acknowledgment, either verbal or pecuniary.” (Cooley.)

DESTEM′PER. Syn. Distemper. Colours ground up with size, gum, or white of egg, and water, as in scene painting. The art of executing work in distemper is called ‘distemper painting.’

DETER′GENT. An agent having the power of removing offensive matter from the skin. The name is now generally restricted to applications that tend to cleanse foul wounds and ulcers.

Detergent, Collier’s. Prep. From liquor of potassa, 2 fl. dr.; rose water, 5¹⁄₂ fl. oz.; spirit of rosemary, ¹⁄₂ fl. oz.; mix. One of the best applications known to free the head from scurf, when the hair is strong and healthy. The head should be afterwards sponged with clean, soft water.

DETONA′TION. See Fulminating Compounds.

DEUTOX′IDE. See Oxides.

DEUTSCHE SIEGESTROPFEN—German Triumphal Drops (Schmidt). 480 grammes of a brown fluid with an agreeably sweet spirituous and aromatic taste, containing in a hundred parts five parts of the portion soluble in weak spirit of cloves and orange peel, 29 parts sugar, 36 parts alcohol, and 30 parts water. (Wittstein.)

DEW-POINT. The temperature at which dew begins to form, as observed by a thermometer. It varies with the humidity of the atmosphere.

DEX′TRIN. C₆H₁₀O₅. Syn. Starch gum, Dextrina, Dextrinum, British gum. A soluble substance resembling gum, formed by the action of dilute acids at the boiling temperature, and by infusion of malt, at about 160° Fahr., on starch. It is also formed when potato starch and some of the other farinas are exposed to a heat of about 400°. See Diastase and Gum (British).

DEX′TRO-RACE′MIC ACID. See Racemic acid.

DIABE′TES. See Urine.

Diabetes (Saccharine). The symptoms observed in this generally fatal ailment are the passing of an excessive quantity of pale, straw-coloured urine, of high specific gravity, containing more or less grape sugar; great thirst and hunger, obstinate dyspepsia, constipation, an unpleasant odour from the feet, or perspiration of the arm-pits, and bodily debility, and emaciation. All these symptoms vary in intensity according to the course and duration of the disease, which is frequently accompanied with hectic fever, cough, and sometimes carbuncles, and generally ends in consumption or some organic disease. The flow of urine sometimes reaches as much as eight gallons in 24 hours; the average quantity, however, is about two gallons. The specific gravity of the urine varies between 1030 and 1070. The quantity of sugar excreted in the twenty-four hours differs greatly, ranging from half a pound to three pounds.

In the treatment of diabetes, great attention should be paid to diet, which should consist principally of digestible, broiled, or roasted meat, gluten and bran bread (these latter being substituted for ordinary bread, which with sugar must be especially avoided), liquids in moderate quantity, of which the most preferable are weak beef tea or mutton broth. If the thirst is extreme, it is best assuaged by drinking water acidulated with phosphoric acid. Spirituous liquids as well as saline aperients should be eschewed. Claret is, however, a suitable beverage.

Small doses of laudanum, given three or four times a day, have been found of great service.

Dr Watson recommends also the administration of creosote. The bowels must be regulated by means of mild aperients. Warm baths are also of use, as they augment the secretion of the skin. The disease may be kept under by administering from twenty to forty minims of tincture of perchloride of iron, 3 times a day. The above treatment is inserted for the guidance only of emigrants and others unable to obtain professional aid; wherever this can be obtained, no time should be lost in seeking it. This is the more important, since the earlier the patient has recourse to the proper remedies, the greater are the chances of recovery.

Horses. The disease occurs, although rarely, in horses. It is not known either in cattle or dogs. The treatment consists in depriving the animal for some weeks of food containing starch, or other matters capable of forming sugar. He must be fed on meat soup and cooked animal diet, to which he quickly becomes reconciled. The strength must be kept up by means of tonic. To counteract the intense thirst, Mr Finlay Dun recommends the following to be given three times a day in water:—A drachm of iodide of potassium, a scruple of iodine, and four drachms of carbonate of soda.

DIACH′YLON. See Plasters.

DIALY′′SER. In practical chemistry, an instrument for separating ‘crystalloids’ from ‘colloids,’ introduced by the late Prof. Graham. In its most convenient form it consists of a hoop of gutta percha, over which a circular piece of parchment paper is stretched. The paper is applied to the hoop while wet, and is kept stretched by a second hoop, by an elastic band, or by a few turns of string. The instrument, when complete, resembles an ordinary tambourine. It is distinguished as the ‘HOOP DIALYSER,’ The fluid to be ‘dialysed’ is poured into the hoop upon the surface of the parchment paper, to a small depth only, such as half an inch, and the dialyser is then floated upon water in a large glass basin. Another form of dialyser, termed the ‘BULB DIALYSER,’ consists of a small glass bell-jar, the mouth of which is covered by a piece of parchment paper. This is suspended or otherwise supported in a large vessel of water in such a manner that the parchment paper septum just dips below the surface. See Dialysis (below), Parchment paper.

DIAL′YSIS. In practical chemistry, the method of separating substances by ‘diffusion’ through a septum of gelatinous matter. When a solution having a sp. gr. greater is introduced into a cylindrical glass vessel, and then water very cautiously poured upon it, in such a manner that the two layers of liquid remain unmoved, the substance dissolved in the lower liquid will gradually pass into the supernatant water, though the vessel may have been left undisturbed, and the temperature remain unchanged. The gradual passage of a dissolved substance from its original solution into pure water taking place, notwithstanding the higher sp. gr. of the substance which opposes this passage, is called the ‘diffusion of liquids.’ From the investigation of the phenomena of this diffusion, the late Prof. Graham derived the remarkable results upon which the method under notice is based. Different substances, when in solution of the same concentration, and under other similar circumstances, diffuse with very unequal velocity. “The range in the degree of diffusive mobility,” says Prof. Graham, “exhibited by different substances, appears to be as wide as the scale of vapour-tensions. Thus, hydrate of potassa may be said to possess double the velocity of diffusion of sulphate of potassa, and sulphate of potassa again double the velocity of sugar, alcohol, and sulphate of magnesia. But the substances named belong, as regards diffusion, to the more volatile class. The comparatively fixed class, as regards diffusion, is represented by a different order of chemical substances (marked out by the absence of the power to crystallise), which are slow in the extreme. Among the latter are hydrated silicic acid, hydrated alumina, and other metallic peroxides of the aluminous class, when they exist in the soluble form; with starch, dextrine, and the gums, caramel, tannin, albumen, gelatin, vegetable and animal extractive matters. Low diffusibility is not the only property which the bodies last enumerated possess in common. They are distinguished by the gelatinous character of their hydrates. Although often largely soluble in water, they are held in solution by a most feeble force. They appear singularly inert in the capacity of acids and bases, and in all the ordinary chemical relations. But, on the other hand, their peculiar physical aggregation, with the chemical indifference referred to, appears to be required in substances that can intervene in the organic processes of life. The plastic elements of the body are found in this class. As gelatin appears to be its type, it is proposed to designate substances of this class as ‘COL′LOIDS,’ and to speak of their peculiar form as the ‘colloidal condition of matter.’ Opposed to the colloidal is the ‘crystalline condition.’ Substances affecting the latter form will be classed as ‘CRYSTAL′LOIDS,’ The distinction is, no doubt, one of intimate molecular constitution.”[257] A certain property of colloidal substances comes into play most opportunely in assisting diffusive preparations. The jelly of starch, that of animal mucus, of pectin, of vegetable gelose, and other solid colloidal hydrates, all of which, strictly speaking, are insoluble in cold water, are themselves permeable when in mass, as water is, by the more highly diffusive class of substances. But such jellies greatly resist the passage of the less diffusible substances, and cut off entirely other colloid substances like themselves that may be in solution. A mere film of the jelly has the separating effect. Now, parchment-paper, when wetted, acts just like a layer of animal mucus or other hydrated colloid, by permitting the passage of crystalloids, but not of colloids; consequently this substance may be used for dialytic septa (see Dialyser, above). The following experiments recorded by Graham will give some idea of the results which may be obtained by dialysis:—

1. Half a litre of urine was placed in a hoop dialyser, which was then floated on a considerable quantity of pure water. Dialysed for 24 hours, the urine gave its crystalloidal constituents to the external water. The latter, evaporated by a water bath, yielded a white saline mass. From this mass urea was extracted by alcohol in so pure a condition as to appear in crystalline tufts upon the evaporation of the alcohol.

2. By pouring silicate of soda into diluted hydrochloric acid (the acid being maintained in large excess), a solution of silica is obtained. But in addition to hydrochloric acid, such a solution contains chloride of sodium, a salt which causes the silica to gelatinise when the solution is heated, and otherwise modifies its properties. Now, such a solution placed for 24 hours in a dialyser of parchment paper was found to lose 5% of its silicic acid (silica) and 86% of its hydrochloric acid. After 4 days on the dialyser, the liquid ceased to be disturbed by nitrate of silver. All the chlorides were gone, with no further loss of silica. What remained was a pure solution of silicic acid, which could be boiled in a flask, and considerably concentrated, without change.

3. Half a litre of dark-coloured porter, with ·05 gramme of arsenious acid added (¹⁄₁₀₀₀₀th part of arsenious acid), was placed on a hoop dialyser, 8 inches in diameter, and the whole floated in an earthenware basin containing 2 or 3 litres of water. After 24 hours the latter fluid had acquired a slight tinge of yellow. It yielded, when concentrated and precipitated by sulphuretted hydrogen, upwards of one half of the original arsenious acid in a fit state for examination.

DIAMANTKITT—Diamond Cement. 50 parts graphite, 15 parts litharge, 10 parts milk of lime, 5 parts slaked lime, intimately mixed with enough linseed oil to make a firm mass. (Hager.)

DIAMANTTROPFEN—Diamond Drops (Dr Allinhead). A combination of the juices of mysterious herbs of tropical climes, which has the power to make all men transparent.

DI′AMOND. The diamond is pure carbon, and differs from the carbon of charcoal and lampblack simply in being limpid, colourless, and highly refractive of light, properties which are generally referred to its crystalline form. The weight, and, consequently, the value of diamonds, is estimated in carats, one of which is equal to 4 grains; and the price of one diamond, compared to that of another of equal colour, transparency, purity, form, &c., is as the squares of the respective weights. The average price of ROUGH DIAMONDS that are worth working is about £2 for the first carat; that of a CUT DIAMOND is equal to that of a rough diamond of double weight, exclusive of the price of workmanship. “To estimate the value of a wrought diamond, ascertain its weight in carats, double that weight, and multiply the square of this product by £2.” (Ure.) Thus, a cut diamond of—

1carat isworth£8

2caratsӣ32

3””£72

4””£128

&c., &c. See Carbon, Gems.

Di′amond Dust. Genuine diamond dust is the powder produced by the abrasion of diamonds against each other in the process of cutting and polishing them. It possesses the valuable property of polishing the gems, and giving “the finest edge to every kind of cutlery.” The discovery of the latter fact, a few years since, led certain dishonest persons to extensively advertise spurious preparations, consisting chiefly of emery powder or powdered quartz, under the name of diamond dust. The factitious articles acquired a very short and bad notoriety. Instead of sharpening cutting instruments, they infallibly destroyed their edge, and were particularly unfortunate in converting razors into saws.

DIAPEN′TE. Syn. Pulvis diapente. Prep. 1. (Ph. E. 1744) Bay-berries, birth-wort, gentian, ivory dust, and myrrh, equal parts. An excellent warm tonic, especially useful in the debility and rickets of children. The substance sold under this name in the shops is an inferior mixture, used principally as a tonic in veterinary practice. The following are the forms commonly adopted in its preparation:—

2. Turmeric, 4 lbs.; laurel berries and mustard, of each 3 lbs.; gentian, 2 lbs. (all in fine powder); mix.

3. Bay-berries, gentian, mustard, and turmeric, equal parts.

4. Gentian, 6 lbs.; bay-berries, 1 lb. This is the formula generally used by the farriers. Sometimes mustard, 1 lb., is added.

DIAPHORET′ICS. Syn. Sudorif′ics; Diaphoretica, Sudorifica, L. Medicines which promote or increase the perspiration. Those that produce this effect in a very marked degree are more particularly called ‘sudorifics.’ The principal diaphoretics are:—warm diluents, as barley-water, gruel, tea, &c.; salts of the alkalies, as the citrates of potassa and soda, acetate of potassa, acetate and carbonate of ammonia, sal-ammoniac, nitre, &c.; preparations of antimony, as antimonial powder, tartar emetic, &c; also alcohol, camphor, Dover’s powder, ipecacuanha, opium, wine, &c.

The use of diaphoretics is indicated in nearly all diseases accompanied by fever and a dry skin, and particularly in febrile and pectoral affections.

DI′APHRAGM (frăm). A partition through or across; a dividing substance. In anatomy, the term is applied to the midriff, a muscle separating the chest or thorax from the abdomen or lower belly. In astronomy and optics the term is applied to a circular ring placed in a telescope or other instrument to cut off the marginal portions of a beam of light. In electricity the name is commonly used to denote the porous partition, cell, or vessel, that separates the fluid containing the positive plate from the fluid which surrounds the negative plate, in a constant voltaic battery. Thin partitions of sycamore, or other porous wood, are occasionally used, but cells made of thin biscuit ware are the most convenient and durable diaphragms. Plaster of Paris, animal membrane, coarse and tightly wove canvas, &c., are used also for the purpose. Plaster cells are also formed by surrounding an oiled cylinder of wood with a hoop of paper, and pouring plaster of Paris, mixed up with water, into the space between the two. See Electrotype.

DIARRHŒ′A. A purging or looseness of the bowels. The causes of diarrhœa are various, but among the most common are the presence of irritating matter, worms, or acidity in the stomach or bowels; and exposure to cold (especially cold to the feet) or sudden changes of climate or temperature.

Treatment. In general, it will be proper to administer a mild aperient, for which purpose rhubarb or castor oil is usually preferred. The dose of the first may be from 20 to 30 grains in sugar, or made into a bolus; that of the second, from ¹⁄₄ oz. to ¹⁄₂ oz., with a little mint or peppermint water. After the due operation of this medicine, opium, astringents, and absorbents, may be taken with advantage, but not in excessive doses, as is commonly the practice. The first and second are indicated when great irritability exists, and the third, in cases of diarrhœa arising from the presence of acidity. Chalk mixture, to which a few drops of laudanum have been added, or the compound powder of chalk and opium, are excellent medicines, and will generally quiet the bowels. A small piece of catechu or hard extract of logwood, sucked in the same way as a lozenge, is a pleasant method of taking either of these powerful astringents, and will generally cure cases of simple diarrhœa arising from excessive peristaltic motion, or want of tonicity of the muscular coats of the intestines.

In bilious diarrhœa, characterised by the bright yellowish-brown colour of the dejections, a dose of blue pill or calomel, assisted by mild diluents and demulcents, and warmth, generally proves efficacious. Small doses of opium are also useful in some cases.

In catarrhal diarrhœa, chylous diarrhœa, and the like varieties, characterised by the dejections being nearly colourless, and consisting chiefly of water and mucus; or white and milky, showing the entire absence of bile; or, being entirely liquid, limpid, and serous (in some cases resembling the washings of flesh), opinions are divided as to the treatment. The majority of the best authorities regard purging as injurious in these varieties, and rely chiefly on warm baths and warm fomentations, with the internal administration of mild salines and diaphoretics, followed by astringents, tonics, and occasional doses of opiates. Choleraic diarrhœa demands a nearly similar treatment.

The diet in every variety of diarrhœa should be light and non-irritating. Glutinous broths, beef tea, and arrow-root, are among the best articles which can be taken. To these may be added a little dry toast. Arrow-root (genuine), either with or without a spoonful of port wine or brandy (preferably the former), will of itself cure all ordinary cases of diarrhœa, if accompanied with repose and a recumbent posture.

Among external remedies, warm and stimulating fomentations, liniments, &c., to the epigastrium and abdomen, will be found useful adjuncts to other treatment. A spoonful or two of laudanum, used as a friction, will generally allay pain, and in many cases settle the bowels when all other remedies have been tried in vain.

Treatment for Animals. If for the horse, give at the commencement of the attack from 2 to 4 dr. of aloes, mixed with 1 oz. of bicarbonate of soda, and the same quantity of ginger in powder; administer clysters occasionally. Cattle may be treated by having administered to them ³⁄₄ lb. of Epsom or common salt, or a pint of linseed oil. Whichever of the two is employed, it must be combined with 2 oz. each of bicarbonate of soda and ginger, and ¹⁄₂ lb. of treacle; 1 oz. of laudanum should be added to the above drenches whenever there is much pain and straining, whether in the horse or cow. Should laxatives fail, aromatics and astringents are called for, and 1 oz. each of tincture of catechu, ginger, and gentian, given in a pint of warm ale, may be tried several times a day for a horse. For cows a double dose is required. Sheep need only half the dose.

DI′ASTASE. A peculiar azotised substance contained in malt, which effects the conversion of starch, first into dextrin, and then into grape sugar.

Prep. A cold infusion of malt is heated to 158° Fahr. (to coagulate in albumen); it is then allowed to cool, and alcohol is added to the filtered liquor, when diastase is precipitated, under the form of a tasteless white powder, which is freely soluble in water.

Prop., &c. Diastase seems to resemble vegetable albumen, but very little is known respecting it, as it has never been got in a state of purity. One part of diastase is capable of converting 2000 parts of starch into grape sugar. Malted barley is said to contain ¹⁄₅₀₀th part of this substance; yet this small portion is quite sufficient to convert the starch of the malt into sugar during the operation of mashing, in the manufacture of beer. See Brewing, Dextrin, &c.

DICTA′MIA. A nutritious, dietetic article. Prep. (Beasley.) Sugar, 7 oz.; potato arrow-root, 4 oz.; flour of brent barley (Triticum monococcum), 3 oz.; Trinidad and Granada chocolate, of each 1 oz.; vanilla, 15 gr.; triturate together.

Dictamia. A strengthening and restorative preparation. Arrowroot, 6 parts; meal of triticum monococcum, 6 parts; chocolate, 4 parts; vanilla, ¹⁄₄ part (Richter). Sugar, 217 parts; bran extract, 92 parts; starch, 125 parts; Caracas and Maragnan cocoa, 30 parts; vanilla, 1 part. (Chevallier.)

DIDYM′IUM. Di. A rare metal, found associated with cerium and lanthanium in the Swedish mineral cerite. See Cerium.

DI′ET. Food or victuals. In medicine food regulated by certain rules, or prescribed for the cure or prevention of disease. The dietetic part of medicine is no inconsiderable branch, and deserves a much greater share of regard than it commonly meets with. A great variety of diseases might be removed by the observance of a proper diet and regimen, without the assistance of medicine, were it not for the impatience of the sufferers. On all occasions it may come in as a proper assistant to the cure, which sometimes cannot be performed without a due observance of the non-naturals.

Writers on dietetics (DIETETICA, L.) have taken much trouble to divide and classify the numerous articles of food suitable to the various conditions of the body in health and disease; but little practical advantage has resulted from their labours. Low diet, middle diet, full diet, milk diet, farinaceous diet, fruit diet, and vegetable diet, are terms which, under most circumstances, are sufficiently simple to be almost self-explanatory.

DIGES′TION. In chemistry and pharmacy the operation of exposing bodies to a gentle and continuous heat. The best digesters are thin glass flasks and beakers, and the most convenient source of heat is the sand bath. Digestion is often performed to soften and otherwise modify bodies that are to be distilled. In physiology the term is applied to the conversion of food into chyme, or the process of dissolving food in the alimentary canal, and preparing it for circulation and nourishment. In surgery digestion signifies a method of treating ulcers, wounds, &c. See Digestives (below).

DIGESTIBILITY OF DIFFERENT FOODS.

Foods.How cooked.Mean time of chymification in stomach.

h. m.

RiceBoiled1

Eggs, whippedRaw1 30

Trout, salmon, freshBoiled1 30

Venison, steakBroiled1 35

SagoBoiled1 45

MilkBoiled2

Eggs, freshRaw2

MilkRaw2 15

TurkeyBoiled2 25

GelatinBoiled2 30

Goose, wildRoasted2 30

Pig, suckingRoasted2 30

Lamb, freshBroiled2 30

Beans, podBoiled2 30

Potatoes, IrishBaked2 30

ChickenFricassed2 45

Oysters, freshRaw2 55

Eggs, freshSoft-boiled3

Beef, lean, rareRoasted3

Mutton, freshBoiled3

Bread, cornBaked3 15

ButterMelted3 30

Cheese, old, strongRaw3 30

Potatoes, IrishBoiled3 30

BeefFried4

Veal, freshBroiled4

Fowls, domesticRoasted4

Ducks, DomesticRoasted4

Veal, freshFried4 30

Pork, fat, and leanRoasted5 15

CabbageBoiled4 30

The results recorded in the above table, giving the respective time required for the digestion of different foods, were obtained by Dr Beaumont, through his being enabled to watch the process of digestion actually going on in the stomach of a man, who had received a wound in that organ, by which part of it was laid bare, and could thus be seen into.

The above data were controlled by a series of independent experiments, which consisted in digesting different foods in a solution of gastric juice, and heating the mixture to 100°. The relative results of both sets of experiments were found to agree pretty closely; and they have since, on the whole, being confirmed by the researches of other physiologists.

DIGES′TIVES. In surgery substances which, when applied to wounds or tumours, induce or promote suppuration. All stimulating applications are of this class. Heat is a most powerful digestive agent. The action of digestives is opposed to that of DISCUTIENTS, which repel or resolve tumours and indurations.

DIGITA′LIN. Syn. Digita′lia. A vegetable principle discovered by M. Royer in Digitalis purpurea, or purple foxglove.

Prep. 1. (Majendie.) Foxglove leaves (powdered), 1 lb., are digested in ether, first in the cold, and then heated under pressure; when the whole has again become cold, the liquor is filtered (rapidly), and the ether is distilled off in a water bath; the residuum is dissolved in water, the filtered solution treated with hydrated oxide of lead, the whole gently evaporated to dryness, and the dry residuum again digested in hot ether; from this solution the alkali is obtained, by evaporation and repeated resolutions, in a crystalline form.

2. (Homolle and Henry.) Foxglove leaves (carefully dried and powdered), 2¹⁄₂ lbs., are digested in rectified spirit, and the tincture expressed in a tincture press; the spirit is then distilled off, and the residual extract treated with distilled water, ¹⁄₂ pint, acidulated with about 2 fl. dr. of acetic acid, a gentle heat being employed; some animal charcoal is then added, and the whole filtered; the filtrate is then diluted with water, and partly neutralised with ammonia; a fresh-made, strong decoction of galls is next added; a copious precipitation of tannate of digitalin ensues; the precipitate is washed with water, and mixed with a little alcohol, after which it is triturated with litharge (in fine powder) and exposed to a gentle heat; the whole is now digested in alcohol, the tincture treated with animal charcoal, and evaporated; the dry residuum is, lastly, treated with cold sulphuric ether, which takes up some foreign matter, and leaves the digitalin. 2 lbs. 8 oz. of the dried leaves yield 140 to 150 gr. of the digitalin.

Prop., &c. White, inodorous, porous masses, or small scales; it crystallises with difficulty, is intensely bitter, and excites violent sneezing when smelled to; dissolves freely in alcohol; scarcely soluble in cold ether; and takes 2000 parts of water for its solution; it is neither basic nor alkaline; concentrated colourless hydrochloric acid dissolves it, forming a characteristic solution which passes from yellow to a fine green. (Homolle.) It is one of the most powerful of known poisons, being fully 100 times stronger than the powdered leaves of the dried plant. It is used in the same cases.—Dose, ¹⁄₆₀ to ¹⁄₃₀ gr.; either made into pills or dissolved in alcohol and formed into a mixture. Owing to the difficulty and uncertainty connected with dispensing such small quantities, it is now seldom employed in this country.

Digitalin, Crystallised. Digitalis leaves from the Vosges, in rather fine powder, 1000 grams; neutral lead acetate, 250 grams; distilled water, 1000 grams. The digitalis should be collected in its second year just when the first flowers appear. With respect to the lead acetate, it is very important that it should not have an alkaline reaction; a slight acidity would be preferable. The lead salt is dissolved in the cold water, the powder added and thoroughly mixed, the whole passed through a sieve and left in contact twenty-four hours, taking care to mix it from time to time. The mixture is then packed sufficiently in a displacement apparatus, and exhausted with 50° alcohol, until it no longer yields any bitterness. About six parts of liquor are thus obtained, and this is neutralised exactly with sodium bicarbonate dissolved to saturation in cold water; about 25 to 30 grams will be required. When effervescence ceases, the alcohol is distilled, and the liquor remaining is evaporated in a water bath down to 2000 grams; it is then left to cool and diluted with its weight of water. Two or three days afterwards the clear liquor is decanted off, by means of a syphon, and the precipitate drained upon a linen filter. When freed from the extractive liquor the precipitate weighs about 100 grams. It is suspended in 1000 grams of 80° alcohol, and the whole passed through a metal sieve or a fine cloth; the turbid liquor obtained is heated to ebullition, and to it is added a solution containing 10 grams of neutral lead acetate; the heating is continued a few moments, and the liquor is then left to cool and filtered. The deposit in the filter is washed with alcohol to remove any liquor it may retain, and then pressed. To this liquor is added 50 grams of finely powdered vegetable charcoal that has been washed with acid and afterwards with water until quite neutral, and it is then distilled, the residue being heated for some time in a water bath, it being very important that all the alcohol should be driven off. A little water is added to replace what may evaporate; the residue is allowed to cool, then drained upon the cloth that was used to separate the precipitate, and the carbonaceous mass is washed with a little water to remove the last portion of the coloured liquor. The carbonaceous residue is then dried completely in a stove at a temperature not exceeding 100° C., and exhausted by displacement with pure chloroform until it passes colourless. This liquid is distilled to dryness, and a few grams of 95° alcohol are placed in the retort, and evaporated to drive off the last traces of chloroform.

The residue is crude digitalin with viscous and oily matter. It is dissolved with heat in 100 grams of 90° alcohol, and 1 gram of neutral lead acetate dissolved in a little water added, together with 10 grams of animal charcoal in fine granules without powder that has been treated with hydrochloric acid, and washed until the washings are no longer acid. After boiling for ten minutes it is allowed to cool and settle, and then filtered in a glass cylinder furnished with a tight cotton plug, through which it passes quickly and clear. The black deposit is added last, and exhausted of all bitterness with alcohol. After distillation the digitalin remains as a grumous crystalline mass, now only contaminated with the coloured oil. A little aqueous liquor that occurs with it is separated and the weight of the impure digitalin is taken in the previously tarred vessel. The digitalin is then dissolved with heat in exactly sufficient 90° alcohol for its solution (from 6 to 12 grams). Any alcohol evaporated is replaced, and then to the cooled solution is added, sulphuric ether rectified at 65°, to half the weight of the alcohol employed; after mixing, distilled water equal to the weight of the alcohol and ether combined is added, and the flask is closed and shaken. Two layers are formed: the upper is coloured, and consists of the ether which has taken up the fat oil; the lower is colourless, and contains the digitalin, which being now free quickly crystallises. The flask is placed in a cool place. Two days afterwards the whole is thrown into a small cylinder furnished with a moderately tight cotton plug; the mother liquor runs off, and then the coloured layer, and the small quantity that remains adherent to the crystals, is removed by a little ether. Thus obtained, this first crystallisation of digitalin is slightly coloured; it is sufficiently pure, however, for its weight to be taken in an analysis; one tenth being deducted for the digitalin it still contains. To obtain it perfectly white, two purifications are necessary, but first a treatment with chloroform is indispensable to separate the remainder of the digitalin which injures its purity.

The digitalin, well dried and reduced to a fine powder, is dissolved in 20 parts of chloroform, and the solution is filtered in a cylinder through a tight cotton plug. The liquor passes limpid; it is distilled to dryness, and a little alcohol is poured into the retort, and evaporated to remove the last traces of chloroform.

The digitalin is dissolved in 30 grams of 90° alcohol, 5 grams of washed granular animal black added, and the whole boiled for 10 minutes; the liquor is filtered and the charcoal exhausted as before indicated; and, lastly, it is distilled, the digitalin in dry crystals is found on the sides of the vessel, but it is still slightly coloured. To obtain it perfectly white it is dissolved with heat in exactly sufficient 90° alcohol (about 6 to 8 grams); to the solution is added ether equal to half the weight of alcohol employed, and double the quantity of distilled water, and the flask is closed and agitated; the crystallisation commences quickly. The ether does not separate. It is exposed to the coolness of the night, and by the next day nearly the whole of the digitalin is deposited in small groups of white needles, that which retains colouring matter remaining in the mother liquor. The whole is thrown into a cylinder and the crystals washed with ether as before described. 1000 grams of Vosges digitalis of good quality yields about 1 gram of crystallised digitalin. Digitalin occurs under the form of very white light crystals, consisting of short slender needles, grouped around the same axis. It is very bitter and scarcely soluble in water. 90° alcohol dissolves it well, anhydrous alcohol dissolves it less freely. Pure ether dissolves only traces. Chloroform is its best solvent. Brought into contact with a small quantity of hydrochloric acid, digitalin is coloured emerald green, and this reaction is favoured by a very slight heat. From ‘Formulæ for New Medicaments, adopted by the Paris Pharmaceutical Society.’

DILL. Syn. Anethum (Ph. L. & E.), L. The fruit (seed) of Anethum graveolens, or garden dill, Anethi fructus, B. P. Dill is an aromatic stimulant and carminative. The Cossacks employ it as a condiment; and in this country it is frequently employed to heighten the relish of soups and pickles, especially cucumbers. Dill water is a favorite remedy of nurses to promote the secretion of milk, and to relieve the flatulence and griping of infants.—Dose, of the powder, 10 gr. to ¹⁄₂ dr., or more. Oil of dill (OLEUM ANETHI) and dill water (AQUA ANETHI) are officinal in the pharmacopœias.

DIL′UENTS. Syn. Diluentia, D. Aqueous liquors; so named because they increase the fluid portion of the blood. Tea, barley-water, water-gruel, and similar articles, are the most common diluents, after pure water. The copious use of diluents is recommended in all acute inflammatory diseases not of a congestive character, and to promote the action of diuretics and sudorifics.

DINNER PILLS. See Pills.

DIOS′MA. Syn. Bookoo, Buku; Folia barosmæ, F. diosmæ, L.; Buchu (Ph. L.), Bucku (Ph. E.), Diosma (Ph. L. 1836). “The leaves of Barosma serratifolia, B. crenulata, and B. crenata.” (Ph. L.) These species were all included by De Candolle in the genus Diosma. Buchu is principally employed in chronic affections of the urino-genital organs, especially that of the mucous membrane of the bladder, attended with copious discharge of mucus.—Dose, 20 gr. to ¹⁄₂ dr. of the powder, taken in wine; or made into an infusion or decoction.

The officinal buchu leaves are “glabrous, glandular; either linear-lanceolate with small serrations, or ovato-oblong, obtuse, crenated, ovate or obovate, serrated.” (Ph. L.) Their odour somewhat resembles that of rue, and their taste is warm and mint-like.

DIOS′MINE. A bitter extractive matter, obtained by Brande from buchu leaves. It is very soluble in water, but not in alcohol and ether.

DIPHTHERIA. A contagious disease affecting the throat and adjoining parts. A false membrane forms on the mucous lining of the several parts of the throat. This alarming malady generally commences with a little soreness of throat attended with fever; sometimes, however, the fever may not come on for some days after the sore throat has shown itself. An ash-coloured spot makes its appearance on one or both tonsils. This spreads to other parts, extending in doing so, over the soft palate and uvula, inclosing the latter in a sheath. Sometimes a thin red line surrounds the opaque membrane thus formed. As the disease proceeds this opaque and false membrane tends to enlarge itself, and may spread down the gullet into the stomach, or, what is more dangerous still, it may involve the mucous membrane of the larynx, and thence extend along the windpipe into the bronchial tubes. When this is the case the disease is accompanied with cough, and the peculiar noise of croup; harsh, noisy breathing. There also frequently runs from the nostrils a thin acrid secretion, smelling very offensively, and often tainting the whole atmosphere of the room.

By the inexperienced diphtheria is almost always mistaken for ulcerated sore throat.

As in croup, part of the exudation or false membrane is often coughed up; sometimes it peels off from the tonsils. Some pathologists think that minute particles of this membrane, loosely adhering to drinking vessels, linen, sheets, the night-dress, &c., of the patient, may be the means of communicating the disease; by others, however, this surmise is not accepted. The absence of certainty on this point does not remove the stringent necessity of thoroughly cleansing and disinfecting everything with which the secretions of the patient come into contact.

The foregoing has been written with the object of enabling the reader to detect the only symptoms by which this dangerous disease manifests itself, in order that he may seek medical assistance with which to combat the complaint as promptly as possible.

After stating thus much, it is needless to say that we only recommend the adoption of the following treatment, in the extreme case of emigrants and others unable to obtain the services of a medical practitioner. A saturated solution of borax in the form of a gargle should be first used, and used without stint. Should this fail to arrest the formation of the membrane, then a strong solution of alum should be employed instead; or alum in powder should be applied to the throat every half hour or hour. When children are to be submitted to this treatment, the alum instead of being used as a gargle may be mixed with honey, and in this condition laid on the parts with a feather; or the powdered alum may be blown on the affected parts with a tube. Tincture of perchloride of iron, diluted hydrochloric acid, and chlorate of potash are also said to have been used successfully as topical applications. The diet should consist of rich nourishing food, such as strong beef tea and mutton broth, aided by port wine. The internal remedies embrace quinine or bark, tincture of perchloride of iron, pernitrate of iron, chlorate of potash, and small, but repeated doses of the mineral acids. Dr Gardner, in his useful work ‘Household Medicine,’ says, “a definite plan said to have been successful is to employ as a gargle a solution of chlorinated soda half an ounce, syrup half an ounce, water six ounces, mixed. At the same time give internally four drops of the solution every two hours, for two days, then add quinine. We may add that if this latter prescription be used the diet before indicated should be adopted.”

DISCU′TIENTS. In surgery, substances or agents which disperse or resolve tumours, &c. See Digestives.

DISH-COVERS. As these are made of various materials they must be cleaned and polished with the substances best adapted for each. All kinds of dish-covers directly they come from table should be washed free from grease and wiped dry.

Plated and silver dish-covers should be polished with plate powder; that free from mercury should be preferred. When dish-covers (as is usually the case) are made of block tin, they should be polished, by first rubbing them with sweet oil, and then dusting over the oil finely powdered whiting; finishing off the polishing with soft rags. All the best covers are provided with movable handles, which must be removed during the process of cleaning.

DISINFECT′ANT. An agent which absorbs, neutralises, or destroys, putrescent effluvia, miasmata, or specific contagia, and thus removes the causes of infection. The principal disinfectants are chlorine, iodine, bromine, the so-called chlorides of lime and soda, chloride of zinc, ozone, carbolic acid, the alkaline manganates and permanganates, peat charcoal, the fumes of nitric and nitrous acid, sulphurous acids, heat, and ventilation. The last two are the most efficient and easily applied. The clothing, bedding, &c., of patients labouring under contagious diseases may be effectually (?) disinfected by exposure to a temperature a little higher than that of boiling water, for about an hour. Neither the texture nor colour of textile fabrics is injured by a heat of even 250° Fahr. (Dr Henry.) See Disinfecting Chambers.

It is a practice at some of the workhouses to bake the clothes of the paupers who have the itch, or who are infested with vermin. The soaking and boiling of clothes in the absence of being able to bake them is by no means a bad method for disinfecting them. The process is rendered the more effective by adding to the water in which they are immersed or boiled 1 part of strong solution of chloride of lime to 20 or 30 parts of water; or carbolic acid in the proportion of 1 part of the pure acid to 100 parts of water. In the German army, if the clothes cannot be baked they are soaked for 24 hours in water containing 1 part of sulphate of zinc to 120 of water, or 1 part of chloride of zinc to 240 of water, after which they are washed in soap and water and dried.

Quicklime rapidly absorbs carbonic acid, sulphuretted hydrogen, and several other noxious gases, and is therefore commonly used as a wash for the walls of buildings. Acetic acid, camphor, fragrant pastilles, cascarilla, brown paper, and other similar substances, are frequently burnt or volatilised by heat, for the purpose of disguising unpleasant odours, but are of little value as disinfectants. The sulphates of iron and zinc have the property of rapidly destroying noxious effluvia. A quantity of either of these sulphates thrown into a cesspool, for instance, will in a few hours render the matter therein quite scentless. Of gaseous disinfectants, “sulphurous acid gas (obtained by burning sulphur) is preferable, on theoretical grounds, to chlorine. No agent checks so effectually the first development of animal and vegetable life. All animal odours and emanations are immediately and most effectually destroyed by it.” (Graham.) See Antiseptic, Deodoriser, Fumigation, Infection, Ozone, Carbolic acid, Salicylic acid, Bacteria as originators of disease, Lime, Chloride, Charcoal, also the Disinfecting Compounds given below.

Dr Wynter Blyth divides disinfectants into two great classes:—Gaseous, and solid or liquid.

I. Volatile, in the form of Gas or Vapour.

1. Substances which, like the halogens, appear to form substitution compounds, e.g.

Chlorine,

Bromine,

Iodine.

2. Substances which probably combine chemically, and thus destroy contagion:

Sulphurous acid,

Nitrous acid,

Fumes of other acids.

3. Oxidising substances, such as—

Pure air,

Oxygen,

Ozone.

4. The volatile oils, &c. Feeble disinfectants, supposed, however, to oxidise—

Camphor,

Oil of hops,

Oil of rue,

Oil of rosemary,

Oil of chamomile.

II. Solid or Liquid Disinfectants.

1. The chlorides of different metals, earths, or bases:

Chlorides of the alkalies,

Chlorides of iron,

Chlorides of copper,

Chlorides of manganese,

Chlorides of zinc,

Chlorides of aluminium,

Chlorides of lime,

Chlorides of mercury,

and, in fact, all chlorides which are soluble.

2. All soluble sulphates, especially sulphates of iron and aluminium.

3. All soluble sulphites.

4. Some acetates, as acetate of iron.

5. Some nitrates, such as the nitrates of potash and soda.

6. Certain agents which appear to arrest putrefaction or condense certain gases, &c., without either destruction or oxidation:

Carbolic acid,

Tar acids,

Charcoal,

Great cold,

Heat sufficient to dry organic substances, but not to char them.

7. Preservative liquids and solutions. Many of these act by coagulating the albumen of organised bodies:

Antiseptics,

Alcohol,

Solutions of corrosive sublimate,

Solutions of common salt,

Solutions of saltpetre.

8. Destructive agents. Not true disinfectants, they act not by disinfection, but by destruction:

A dry heat of 200° to 400° F.,

The strong undiluted acids and alkalies.

9. Agents which act in many ways, partly by condensing gases, partly by absorbing moisture, and partly by a peculiar action on organic matter analogous to tannin:

Dry earths,

Clays,

The natural and artificial compounds of aluminium.

The table on the next page is a summary by the late Dr Letheby of some experiments made by Drs Dougall and Calvert, with the view of determining the relative powers possessed by certain substances of arresting putrefaction, as measured by their action in preventing the germination of animalcules and fungi, and the development of vaccine lymph.[258]

Disinfecting Compounds. 1. (Sir Wm. Burnett’s Disinfecting Liquid.) A concentrated solution of chloride of zinc. See Zinc.

2. (Collins’ Disinfecting Powder.) A mixture of dry chloride of lime, 2 parts, and burnt alum, 1 part. Used either dry or moistened with water. See Lime.

3. (Condy’s Disinfecting Fluids.) Solutions of the alkaline manganates and permanganates. Although this is an excellent and rapid deodoriser, and makes a most serviceable dressing for fetid sores, it must be borne in mind that it is in no sense an aërial disinfectant, its action being limited to the solid or liquid matters only with which it is brought into immediate contact. It exercises no corrosive action, but it is open to the objection that it leaves a brown stain upon linen. See Manganese.

4. (Ellerman’s Deodorising Fluid.) This is said to consist chiefly of the perchlorides and chlorides of iron and manganese.

“In a report addressed to the Metropolitan Board of Works in 1859, Drs Hoffmann and Frankland stated that the perchloride of iron was the cheapest and most efficient deodoriser that could be applied to sewage.” (Beasley.)

5. (Labarraque’s Disinfecting Solution; Liquor sodæ chlorinatæ, Ph. L. & D.) A solution of chlorinated soda, or, as it is commonly called, ‘chloride of soda.’ M. Labarraque made known this valuable disinfectant in 1822, and obtained the prize of the French ‘Society for Encouraging National Industry’ for its introduction.

6. (Ledoyen’s Disinfecting Fluid.) A solution of nitrate of lead, 1 part, in about 8 parts of water; or, of litharge, 13¹⁄₂ oz., in nitric acid (sp. gr. 1·38), 12 oz., previously diluted with water, 6 pints. Sp. gr. 1·40.

7. (Siret’s Disinfecting Compounds.)—a. A mixture of sulphate of lime, 53 lbs., sulphate of iron, 40 lbs., sulphate of zinc, 7 lbs., and peat charcoal, 2 lbs., made into balls.

b. Sulphate of iron, 20 parts; sulphate of zinc, 10 parts; tan or waste oak-bark (in powder), 4 parts; tar and oil, of each 1 part; as before. Used for deodorising cesspools, &c.

8. (Bisulphide of Carbon.) This generates, when burnt, sulphurous acid, and is, therefore, a very valuable disinfectant. Its highly inflammable nature, however, renders the adoption of certain precautions necessary in its use. A method of employing it in the form of fumigation will be found under the article “Fumigation.”

9. Dry salicylic acid volatilised from a hot plate purifies the air, and perfectly disinfects the walls of a closed room. (Von Heyden.)

10. “Sanitas” is the name given by Mr Kingzett, its discoverer, to a new liquid antiseptic and disinfectant, containing peroxide of hydrogen and camphoric acid, and obtained by the atmospheric oxidation of turpentine. Sanitas is said by its inventor to possess the great advantages of being non-poisonous, and to exercise no injurious effects either on clothing or furniture. It is stated that its antiseptic power is distributed between the peroxide of hydrogen and camphoric acid, the peroxide of hydrogen being able to evolve large quantities of oxygen, which in this state is nascent, and of a powerful and oxidising character.

11. Cooper’s Universal Disinfecting Powder. According to Professor Wanklyn this powder contains 70 per cent. of mixed chloride of sodium and chloride of calcium, and about 6 per cent. of anhydrous sulphate of zinc (equal to about 12 per cent. of hydrated sulphate), a little insoluble matter, and 15 per cent. of moisture.

12. Dr Bond’s Cupralum and Ferralum. The first of these disinfectants is stated to be a mixture of the sulphates of copper and aluminium, with potassic dichromate and turpentine. Its inventor claims for it that it possesses great power of coagulating albumen and high value both as an antiseptic and deodorant. Ferralum is a mixture of ferrous and aluminic sulphates, turpentine, and carbolic acid. Its chief use is for flushing sewers and in deodorising cesspools, urinals, &c.

13. Bayard’s Disinfectant. A mixture of sulphate of iron, clay, lime, and coal tar.

Summary of the Experiments made by Dr J. Dougall, and by Dr Crace Calvert, on the action of various Antiseptics on Protoplasmic and Fungus Life, and on Vaccine Lymph.

KEY:

A - Quantity required to prevent Animalcules in six days.

B - Number of Days before Life appeared in a solution containing 1 of substance in 500 water and ¹⁄₂ drachm of following—

C - Number of Days before Vibrio Life appeared in a solution of Albumen containing 1 of substance in 1000 of solution.

D - Beef Juice.

E - Sol. of Egg Albumen.

F - Reaction of the Solution.

G - Infusion of Hay. 1 part in—

H - Human Urine. 1 part in—

I - Beef Juice and Egg Albumen. 1 part in—

J - Average of all. 1 part in—

K - Effect on Animalcules in Putrid Beef Juice and Egg Albumen, when added in proportion in third column.

L - Animalcules.

M - Fungi.

N - Animalcules.

O - Fungi.

P - Effect of the Vapour or Gas during 24 hrs. on Vaccine Lymph.

Q - Animalcules.

R - Putrid Odour.

S - Fungi.

T - Mouldy Odour.

Substances used.EXPERIMENTS MADE BY DR JOHN DOUGALL, OF GLASGOW.EXPERIMENTS BY DR CRACE CALVERT.

FAKBPC

GHIJDEQRST

LMNO

Acids.

Mineral.

SulphurousAcid.2505050117Death.244 P.8Over 100Killed.11Over 4021Over 40

Nitric”400400200333”184 P.155 T.”10501023

Hydrochloric”500400100333”284 P.9Over 100”————

Sulphuric”800500100467”Over 100Over 1003010 T.—9—911

Chromic”4000140012002200—7838 P.Over 100Over 100—————

Organic.

CarbolicNeutral.300300200267None.1250 T.3836 P.None.Over 40Over 40Over 40Over 40

Cresylic”————”————”””””

AceticAcid.3502510125—————Killed.30—950

Picric”350350350350Death.4411 P.Over 10044 P.—17Over 4019Over 40

Benzoic”700700200533”Over 100Over 100”Over 100—————

Alkalies.

LimeAlk.——————————1319Over 40Over 40

Potash”3005010120Death.—————16———

Soda”——————————23311829

Ammonia”——————————245020Over 40

Haloids.

Iodine tinctureNeutral.40040050283Death.180 T.15Over 100—————

Chlorine gasAcid.—————————Killed.72121—

Chloride limeAlk.20020025142Death.2727 T.40Over 100”71816—

Chloride zincAcid.300300300300”4Over 10018”—Over 40Over 4050Over 40

Chloride aluminum”2000500300933—194 P.Over 1008 P.—10”2150

Sulphates, &c.

Bisulphite limeAcid.100502558Death.492 T.9Over 100—112114Over 40

Sulphate zinc”300300200267”304 P.9070 P.—————

Sulphate iron”500500100367?145 T.3540 T.—7Over 4015—

Common alum”800500100467—143 P.3815 T.—————

Sulphate copper”10001000800933Death.8620 P.Over 100Over 100—————

Permanganate potashNeutral.500200125275None.—————95022Over 40

Alcohol”3505020140Death.44 T.10Over 100—————

Camphor”30015050167None.————None.————

Turpentine”——————————14Over 4042Over 40

Note.—In the first set of Dr John Dougall’s experiments 3 drachms of a solution of the strength mentioned were treated with 1 drachm of a filtered infusion of hay, or with half a drachm of urine or half a drachm of the mixture of beef juice and egg-albumen. In the second set of experiments equal parts of a putrid solution of beef juice and egg-albumen, full of living animalcules, and of the solution of the various substances of the strength known to be preventive of life (as in third column), were mixed together, and the results immediately noted. In the third set of experiments 3¹⁄₂ drachms of distilled water, containing 1 in 500 of the substances named, were treated with half a drachm of filtered beef juice, or half a drachm of a solution consisting of 1 part white of egg to 4 parts water. In the last set of experiments, separate minims of vaccine lymph were exposed to the several vapours for 24 hours, and the dried spot in each case was moistened with glycerin and water, and sealed in a capillary tube until an opportunity for vaccination occurred, when the whole of the diluted lymph was used in one insertion so as to ensure its full effect.

In Dr Crace Calvert’s experiments, 0·026 of a gramme of the substance was added to 26 grammes (1 to 1000) of a solution of albumen containing 1 part white of egg to 4 parts pure distilled water.

The Animalcules observed were Monads (microphymes), Vibrios, and their cell segments (microerphymes), Bacteria (microzymes), Amœba, &c.; and the Fungi were Torula, Mycelium, Penicilium, &c., indicated in Table by letters T and P. Putrefaction was always characterised by a putrid odour, an alkaline reaction, and the presence of animalcules; whereas Mouldiness and Fermentation were distinguished by a mouldy or musty odour, an acid reaction, and the presence of Fungi.

14. Larmande’s Antimephetic Liquor. A solution of the sulphates of zinc and copper.

15. Thymol. From experiments made with this substance it appears to be a very powerful and valuable antiseptic, and likely, because of its non-poisonous and non-irritant qualities, to supplant carbolic acid in various branches of surgical practice, in which this latter agent has hitherto been employed; such, for example, as a dressing for wounds, ulcers, and as a topical application for certain skin eruptions, &c. Its difficult solubility and price (spite of its much greater antiseptic power), however, for the present at any rate, preclude it from being made available as an ordinary common disinfectant, as this term is generally understood. See Thymol.

16. Silicate of Soda. It is stated that this salt has considerable anti-putrefactive powers.

17. Aluminised Charcoal. This is recommended by Dr Stenhouse as a cheap and very efficient decolorising agent. It is made by dissolving in water 54 parts of the sulphate of alumina of commerce in water, and mix it with 92¹⁄₂ parts of finely powdered wood charcoal. When the charcoal is saturated it is evaporated to dryness, and heated to redness in covered Hessian crucibles till the water and acid are dissipated. The charcoal contains 7¹⁄₂ per cent. of anhydrous alumina.

The natural disinfectants are air and water.

Air, when in violent motion, as is the case during a hurricane, has in many instances been known to arrest the course of certain epidemics; whilst in the form of ordinary ventilation, although inadequate alone to destroy the causes (whatever they may be) of contagion or infection, it is nevertheless found to supplement, to a considerable extent, the application of artificial and specific disinfectants. Hence the paramount necessity of perfect ventilation in all apartments in which the sick are placed, and hence also the measures taken in all hospitals to ensure by this means an increasing supply of fresh air to the wards in which the patients are lying.

The diminution in the amount of sickness prevailing in an army caused by the removal of the soldiers from barracks and placing them in sheds or under canvas is another illustration, tending to show the disinfectant properties possessed by an atmosphere in a state of circulation, when, of course, other hygienic precautions are not neglected.

In Hammond’s ‘Hygiène’ for 1863 the author, who was surgeon-general in the United States army, says that he only met with one instance of hospital gangrene in a wooden pavilion hospital, and not a single one in a tent; and the same result is recorded by Kraus, of the Austrian army in 1859, who says he never discovered that gangrene originated in a tent; that, on the contrary, cases of gangrene at once began to improve when those suffering from the disease were sent from hospital wards into tents. In his work on ‘Practical Hygiène’ Dr Parkes advises all cases of typhus occurring in barracks, whenever practicable, to be sent to tents or wooden huts having badly-jointed walls.

The great solvent power of water, superadded to its being able to hold matters in suspension, renders it a most important disinfectant, and thus enables it in the form of rain to remove from the atmosphere many noxious and pestilential bodies that would doubtless, if allowed to increase, become a source of disease. The air-current which constitutes the ventilation of the House of Commons, before entering the Commons’ chamber, is made to pass over a fine spray of water, by which means it has any dust or other organisms washed out of it. The beneficial effect of rain also in flushing drains and canals, and sweetening the superincumbent air, and of washing out of it many solid as well as gaseous objectionable impurities, is well known. The year 1860 was one of the wettest on record, as it was also one of the healthiest. Dr W. Budd recommends that when a room is to be disinfected, a short time before the process is commenced a tub of boiling water should be placed in the apartment, so that the steam may become condensed on the walls, and diffused throughout the air, as he believes there is a greater chance of ensuring the destruction of the disease germs by the aërial disinfectants than if these latter were allowed to act on the germs in the dry state.

We have already enforced in these pages the importance of the habit of personal cleanliness as being one of the greatest aids to the preservation of health; and although the unstinted use of soap and water will alone fail to effect the removal of any infectious or contagious maladies, their use will be found important auxiliaries in assisting recovery. But personal ablution is not the sine quâ non. The frequent cleansing of our dwellings, streets,[259] alleys (more particularly culs-de-sac), lanes, and the sheds and habitations of animals, by soap and water, or water alone, as well as the removal of all decaying or refuse materials from our midst, is of equal importance, and must not be disregarded, if we desire to make our sanitary surroundings such as they ought to be.

We extract the following from Dr Parkes’ valuable and standard work—‘Practical Hygiene,’

“Disinfection of Various Diseases.

“Exanthemata, Scarlet Fever, and Rothëln. The points to attack are the skin and throat. The skin should be rubbed from the very commencement of the rash until complete desquamation, with camphorated oil, or oil with a little weak carbolic acid. The throat should be washed with Condy’s fluid, or weak solution of sulphurous acid.

“Clothes to be baked, or to be placed at once in boiling water, as directed further back. The clothes should not be washed at a common laundry. Chlorine or euchlorine should be diffused in the air, the saucer being put some little distance above the head of the patient. Carbolic acid and ether or carbolic-acid spray may be used instead.

“Smallpox.—In this, as in all cases, there can be no use in employing aërial disinfectants, unless they are constantly in the air, so as to act on any particle of poison which may pass into the atmosphere.

“The skin and the discharges from the mouth, nose, and eyes are to be attacked. There is much greater difficulty with the skin, as inunction cannot be so well performed. By smearing with oil and a little carbolic acid and glycerin, or, in difficult cases, applying carbolised glycerin to the papules and commencing pustules, might be tried. The permanganate and sulphurious acid solutions should be used for the mouth, nose, and eyes. The clothing should always be baked before washing, if it can be done.

“The particles which pass into the air are enclosed in small dry pieces of pus and epithelial scales; and Bakewell, who has lately examined them, expresses great doubts whether any air purifier would touch them. Still it must be proper to use euchlorine or carbolic acid. Iodine has been recommended by Richardson and Hoffmann.

“Measles.—Oily applications to the skin and air purifiers, and chlorides of zinc and aluminium in the vessels receiving the expectoration, appear to be the proper measures.

“Typhus (Exanthematicus).—Two measures seem sufficient to prevent the spread of typhus, viz. most complete ventilation and immediate disinfection and cleansing of clothes. But there is also more evidence of use from air purifiers than in the exanthemata. The nitrous acid fumes were tried very largely towards the close of last century and the beginning of this in the hulks and prisons where Spanish, French, and Russian prisoners of war were confined. At that time so rapidly did the disease spread in the confined spaces where so many men were kept, that the efficacy even of ventilation was doubted, though there can be no question that the amount of ventilation which was necessary was very much underrated. Both at Windsor and Sheerness the circumstances were most difficult. At the latter place (in 1785), in the hulk, 200 men, 150 of whom had typhus, were closely crowded together; 10 attendants and 24 men of the crew were attacked; 3 medical officers had died when the experiments commenced. After the fumigations one attendant only was attacked, and it appeared as if the disease in those already suffering became milder. In 1797 it was again tried with success, and many reports were made on the subject by army and naval surgeons. It was subsequently largely employed on the Continent, and everywhere seems to have been useful.

“These facts lead to the inference that the evolutions of nitrous acid should be practised in typhus-fever wards, proper precautions being taken to diffuse it equally through the room, and in a highly dilute form.

“Hydrochloric acid was employed for the same purpose by Guyton de Morveau in 1773, but it is doubtless much inferior to nitrous acid. Chlorine has also been employed, and apparently with good results.

“In typhus it would seem probable that the contagia pass off entirely by the skin, at least the effect of ventilation, and the way in which the agent coheres to the body linen seems to show this.

“The agent is not also enclosed in quantities of dry discharges and epidemics, as in the exanthemata, and is therefore less persistent and more easily destroyed than in those cases. Hence possibly the greater benefit of fumigations, and the reason of the arrest by ventilation. The clothes should be baked, steeped, and washed, as in the exanthemata.

“Bubo Plague. The measures would probably be the same as for typhus.

“Enteric (typhoid fever). The bowels’ discharges are believed to be the chief, if not the sole agents in spreading the disease; the effluvia from them escape into the air, and will adhere to walls and retain power for some time, or the discharges themselves may get into drinking-water. Every discharge should be at once mixed with a powerful chemical agent; of these, chloride and sulphate of zinc have been chiefly used, but sulphate of copper (which Dougall found so useful in stopping the growth of animalculæ), chloride of aluminium, or strong solution of ferrous sulphate (1 ounce to a pint of water), or carbolic acid. After complete mixing the stools must be thrown into sewers in towns; but this should never be done without previous complete disinfection. In country places they should be deeply buried at a place far removed from any water supply; they should never be thrown on to manure heaps or on to middens, nor into earth closets, if it can be possibly avoided. As the bedclothes and beds are so constantly soiled with the discharges, they should be baked, or, if this cannot be done, boiled immediately after removal with sulphate or chloride of zinc. It would be less necessary to employ air purifiers in this case than in others.

“Cholera. There can be little doubt that the discharges are here also the active media of the conveyance of the disease, and their complete disinfection is a matter of the highest importance. It is, however, so difficult to do this with the immense discharges of cholera, especially when there are many patients, that the evidence of the use of the plan in the last European epidemic is very disappointing.

“The ferrous sulphate (green vitriol), which has been strongly recommended by Pettenkofer as an addition to the cholera evacuations, was fully tried in 1866 at Frankfurt, Halle, Leipzig, in Germany, and at Pill, near Bristol, and in those cases without any good result. In other places, as at Baden, the benefit was doubtful. It seemed to answer better with Dr Budd and Mr Davies at Bristol; but other substances were also used, viz. chlorine gas in the rooms, and chloride of lime and Condy’s fluid for the linen. On the whole it seems to have been a failure. Ferric sulphate, with or without potassium permanganate, has been recommended by Kühne instead of ferrous sulphate, but I am not aware of any evidence on the point. Carbolic acid was largely used in England in 1866, and appeared in some cases to be of use, as at Pill, near Bristol, and, perhaps, at Southampton. It failed at Erfurt, but, as it is believed the wells were contaminated by soakage, this is perhaps no certain case. Chloride of lime and lime were used at Stettin without any good result, and, on the whole, it may be said that the so-called disinfection of the discharges of cholera does not seem to have been attended with very marked results. At the same time it cannot be for a moment contended that the plan has had a fair trial, and we can easily believe that unless there is a full understanding on the part of both medical men and the public of what is to be accomplished by this system, and a conscientious carrying out of the plan to its minutest details, no safe opinions of its efficacy or otherwise can be arrived at. It would be desirable to try the effect of chromic acid or bichromate of potash.

“With regard to air purifiers little evidence exists. Chlorine gas diffused in the air was tried very largely in Austria and Hungary in 1832, but without any good results. Nitrous-acid gas was used in Malta in 1865, but apparently did not have any decided influences, although Ramon da Luna has asserted that it has a decided preservative effect, and that no one was attacked in Madrid who used fumigations of nitrous acid. But negative evidence of this kind is always doubtful. Charcoal in bulk appears to have no effect. Dr Sutherland saw a ship’s crew severely attacked, although the ship was loaded with charcoal.

“Carbolic-acid vapour diffused in the atmosphere was largely used in 1866 in England; the liquid was sprinkled about with water, and sawdust moistened with it was laid on the floors and under the patients. The effect in preventing the spread of the disease was very uncertain.

“Yellow Fever. In this case the discharges, especially from the stomach, probably spread the disease, and disinfectants must be mixed with them.

“Fumigations of nitrous acid were employed by Ramon da Luna, and it is asserted that no agent was so effectual in arresting the spread of the disease.

“Dysentery. It is well known that dysentery, and especially the putrid dysentery, may spread through an hospital from the practice of the same close stool or latrines being used. As long ago as 1807, fumigations of chlorine were used by Mojon to destroy the emanations from the stools, and with the best effects. The chlorine was diffused in the air, and the stools were not disinfected; but this ought to be done as in enteric fever, and especially in the sloughing form. It is probable that carbolic acid in large quantity would be efficacious.

“With respect to Erysipelas, Diphtheria, Syphilis, Gonorrhœa, Glanders, and Farcy, local applications are evidently required, and carbolic acid in various degrees of strength, and the metallic salts, are evidently the best measures.

“Cattle Plague. The experiments made by Mr Crookes on the disinfectant treatment of cattle plague with carbolic acid vapour have an important bearing on human disease. Although the observations fall short of demonstration there are grounds for thinking that when the air was kept constantly filled with carbolic acid vapour, the disease did not spread.

“So also euchlorine was employed in Lancashire by Professor Stone of Manchester, with apparent benefit. Dr Moffat employed ozone (developed by exposing phosphorus to the air), and he believes with benefit. As such experiments are very much more easily carried out on the diseases of animals than on those of men, it is much to be wished that the precise effect of the so-called disinfectants should be tested by continuing the experiments commenced by Mr Crookes, not only in cattle plague in the countries where it prevails, but in epizootic diseases generally.

“It may be said, in conclusion, that although positive evidence is so deficient, yet, taking into consideration the decidedly great and known effect of many so-called disinfectants, and air-purifiers on organic matters, and the fact that the infectious organic agencies are certainly easily destroyed in most cases (since free ventilation renders many of them inert, and few of them retain their power very long), it is highly probable that the specific poisons of the so-called zymotic diseases are destroyed by some of these chemical methods, and at any rate the careful and constant use of chemical agents for the destruction of the specific poisons in the excreta and discharges from the body, and when they pass into the air, is not only warranted, but should be considered comparative.

“Purification of rooms after infectious diseases. In addition to thorough cleansing of all woodwork with soft soap and water, to which a little carbolic acid has been added (1 pint of the common liquid to 3 or 4 gallons of water), and to removal and washing of all fabrics which can be removed, the brushing of the walls, the room should be fumigated for 3 hours with either the fumes of sulphurous or nitrous acids. Both of these are believed to be superior to chlorine, especially in smallpox. All doors and windows, and the chimney being closed, and curtains taken down, the sulphur is ignited as directed in our article Fumigation.

“In white-washed rooms the walls should be scraped, and then washed with hot lime to which carbolic acid is added.

“Mortuaries and dead-houses are best purified with nitrous acid.”

These directions may be supplemented by the following:—The towels, sheets, articles of clothing, &c., should be boiled in water, or plunged in boiling water containing one to two handfuls of soda to the gallon, before being taken from the room, after which treatment they should be steeped in water containing 4 fluid ounces of carbolic acid to a gallon of water.

Fabrics soiled by the discharges, &c., such as rags, bandages, and dressings, if of little value should be immediately consigned to the flames; but if this be not convenient, they may be treated with carbolic acid and water, in the same manner as directed for towels, sheets, &c.

As soon as any infectious disease sets in, the room of the patient should be at once stripped of curtains, carpet, bed-curtains, valances, and all unnecessary garments, whether in a wardrobe or drawers, as well as of all superfluous furniture, especially chairs stuffed with wool or covered with fabric of any kind.

Disinfections of the apartment by fumigations must be postponed until it is vacated; as before such a time thorough disinfection is impossible.

Infected bedding, &c., should be removed in the boxes made for the purpose, and subjected to the heating process. In most towns provision is made by the Board of Guardians, and under the directions of the medical officer of health, for the disinfection process to be efficiently carried out. See Disinfecting Chambers.

The disinfection of articles of food is accomplished by thorough cooking, boiling in the case of milk, boiling and filtration in the case of water, and complete roasting, stewing, and frying of meat.

The experiments of Mr Crookes (to which reference has been made in the extract taken from Dr Parkes’ ‘Practical Hygiène’) with carbolic acid during the cattle plague possess great practical interest both for the chemist and physiologist.

Of the use of carbolic acid as a disinfectant Mr Crookes, in the Appendix to the Report of the Cattle Plague Commissioners, writes as follows:

“According to the principles laid down, the air must be treated, and where there is no disease there is only a secondary use in treating anything besides the air. Several cowhouses have been treated with carbolic acid with very excellent results. The mode has been, first, to remove from the floor the mass of manure, which too often adheres to it; secondly, to sprinkle the floor with strong carbolic or cresylic acid; next, to wash the walls, beams, and rafters, and all that is visible in the cowhouse, with lime, in which is put some carbolic acid, 1 to 50 of the water used, or with strong carbolic acid alone. Next, to make a solution containing 1 of carbolic or cresylic acid to 100 of water, or, perhaps still better, 60 of water, and to water the yard and fold until the whole place smells strongly of the acid. Only a few farms have been treated in this way, so far as I know, but in each it has been successful. It may be well to give the cattle a little of the weak solution of carbolic acid, but this has not been so fully tried as the external use. The washing of the mouth and of the entire animal with the weak solution may be attended with good results, especially in the early stage of disease; but I know nothing of cure, and speak only hopefully of prevention.

“The animals seem to have an instinct for disinfection, and lick substances touched with this acid. They must not be allowed to drink it, as when strong it blisters the skin, and especially the mouth and tongue.”

Mr Crookes also tried the effect of the acid by injecting it into the veins of the animals, and thus details the results of his experiments:—“It appeared evident that if harm were to follow the injection of carbolic acid, the mischievous effect would be immediate; but that if the fluid could pass through the heart without exerting its paralysing action on that organ, and could get into the circulation, no present ill effects need be anticipated. I therefore determined to push these experiments as far as possible, increasing the quantity of carbolic acid, until it produced a fatal result.

The next operation was on cow No. 11, in which 3 oz. of solution (containing 52¹⁄₂ gr. of pure carbolic acid) were very slowly injected; no bad effect followed. Increasing the dose, cow No. 12 had injected into her vein 4¹⁄₂ oz. of solution (equal to 78³⁄₄ gr. of carbolic acid); this also was followed by no immediate ill effect. Cow No. 13 was then treated with 6 oz. of solution (containing 105 gr. of pure carbolic acid), in two portions of 3 oz. each, five minutes’ interval elapsing between each injection. The first 3 oz. produced a slight trembling, but not so severe as in the case of cow No. 10, as she seemed better in a few minutes. The second dose of 3 oz. was injected. This proved too much, or was pumped in too hurriedly, for almost before I had finished the animal trembled violently, its eyes projected, its breathing became laborious, it fell down and expired. The result could scarcely be attributed to the accidental injection of air into the vein, for the distress began with the injection of the first syringeful, and was only increased by the second; nor is it likely that this accident would happen twice consecutively. I was particularly careful on this point, and the construction of the instrument rendered such an occurrence scarcely possible with ordinary precaution. It is probable that the injection was performed too rapidly, or that the vital powers were lower than usual. In the case of the remaining animal, No. 14, I decided to inject as large a dose as it would bear, stopping the operation at the first sign of trembling, and delivering the liquid very gradually. The first syringeful caused no bad symptoms, and I had just finished injecting the second dose when trembling commenced. It was rather violent for a short time, but soon went off, and in five minutes the animal appeared as well as before.

This cow, therefore, bore without inconvenience the injection of 6 oz. of a 4 per cent. solution, containing 105 gr. of pure carbolic acid. Careful observations with the thermometer were taken before each operation. There were no more diseased beasts on the farm, or I should have carried my experiments still further. On visiting the farm the next day I was told that all the animals seemed better, and on testing them with the thermometer that statement was confirmed. I gave directions that each animal was to be drenched with half a wine-glassful (1 oz.) of carbolic acid in a quart of warm water every morning, but in other respects they might be treated as Mr Tomlinson, a skilful cow doctor, should direct.

“Business now calling me to London, I was unable to watch the further progress of these cases.

“This is to be regretted, as a series of daily thermometric observations would have been of great value in suggesting further experiments. I had, however, frequent accounts sent me. Cow No. 14 continued to improve slowly until convalescent; she is now quite well. Nos. 10, 11, and 12 remained apparently in the same state for four days; they then changed for the worse, and died. It is not improbable that had I been able to inject a further quantity of carbolic acid during the four days in which they were thus hovering between recovery and relapse, it would have turned the scale, and some of them at all events would be now alive and well.

The following table gives the thermometric observations;—

Table showing the results of injecting carbolic acid into the blood of animals suffering from the cattle plague.

No.Grains of Carbolic Acid Injected.Temperature before InjectionSecond Day.Third Day.

F.F.

1026¹⁄₂105·4103·8Better.Died on 6th day.

1152¹⁄₂103·8102·8”Died on 6th day.

1278³⁄₄104·8104·4”Died on 6th day.

14105103·7103·1”Recovered.

If future experiments prove that injection of carbolic acid or other antiseptic will do good, it is an operation very easily performed. I have injected five animals, and taken thermometric observations within an hour. Sulphite or bisulphite of soda apparently occasions some pain, as the animals struggle very much; with carbolic acid I found them tolerably quiet. I have calculated the proportion which the carbolic acid bore to the whole quantity of blood in these operations. Taking the whole amount of blood in the animal at 150 lbs., there were injected into—

No.10,1 part ofcarb. acid, in40,000of blood.

”11,””20,000”

”12,””13,300”

”14,””10,000”

It is worth mentioning incidentally, that in the case of cow No. 14 (which recovered) the proportion of carbolic acid injected into the blood would have been enough to keep from decomposition the whole quantity of that liquid for a considerable time. In Nos. 10, 11, and 12 the proportion of carbolic acid would probably not have been sufficient for that purpose. I am informed by Dr Calvert that cresylic acid has much less coagulating power on albumen than carbolic acid, and my own experiments entirely confirm this statement.”

We have described under “Charcoal” the disinfecting properties of that substance. These properties have been turned to excellent account by Dr Stenhouse, who has invented a charcoal respirator, which, causing the wearer to breathe air drawn through a layer of that substance, and by thus depriving the air so inspired of any noxious gases or exhalations, if present, becomes, if worn in an infected atmosphere, a great safeguard against disease. Dr Letheby was accustomed to use a charcoal respirator when analysing dead bodies and other putrid matters of suspected poisoning, and by so doing never experienced any ill effects, nor was he conscious of the offensive odour which but for its adoption he must have encountered.

Professor Tyndall has suggested for the same purpose a respirator of cotton wool, by means of which the air, being filtered before it enters the lungs, becomes deprived of minute particles of various substances suspended in it, as well as of the germs, which so many pathologists believe to be always present during the prevalence of epidemic maladies, and the cause, when inhaled, of the maladies themselves.

DISINFECTING CHAMBERS. The sanitary authorities of most large cities have made provision for the purification of mattresses, linen, wearing apparel, &c., by means of disinfecting chambers or ovens, in which receptacles the infected articles are subjected for a certain time to hot air. The simplest form of apparatus for this purpose, and one that could be used on an emergency, provided the articles to be disinfected were not too bulky, is a baker’s oven. The drying closet of a good laundry would be so far unsafe, because it would occasionally fail to give a heat sufficient for the destruction of the noxious principles.

The disinfecting chambers employed in Liverpool are arched ovens of solid brickwork, having a depth of 7 feet from front to back, a width of 5 feet from side to side, and a height of 6¹⁄₂ feet from the floor to the crown of the arch. The doors are made of wrought iron, tightly fitting into cast-iron framework. The floors are made of double iron gratings, having alternate openings, so arranged as to admit at pleasure hot air into the chamber. At the top of the arch there is an opening fitted with an iron valve, by which the air of the chamber escapes into an exhausting shaft which is connected with the chimney. The heating is accomplished by means of a cast-iron cockle, the smoke from which escapes by two cast-iron smoke flues, which, after forming a coil for the purpose of affording as great a heating surface as possible, pass along the hot-air passage under the chamber, into a chimney situated at the opposite end.

The cold air is drawn into a brick flue placed underneath the floor of the stokehole into a cavity on each side of the cockle, and thence into a space underneath the chamber, whence it becomes heated by the radiation from the surface of the two cast iron flues. From this cavity or passage it is conveyed at will through the gratings as already described. At the entrance of the cold air flue there is a damper, by which the temperature of the air may be regulated. A heat equal to 280° F. has been registered in this chamber, and as high as 380° in a drying closet over the cockle. Dr French, the medical officer of health for Liverpool, says “that, if necessary, a temperature reaching 500° F. can be attained in these chambers; but this temperature is of course never employed. Experience has proved that from 220° to 250° F. is the most suitable. Instances have been known where fabrics, after being exposed for some length of time to a temperature above 212° F., have sustained injury from being scorched.

In some of the chambers, carbolic acid powder is sprinkled on the floor.

We have taken the liberty of transcribing the following description and plates illustrative of the disinfecting stove used in the Royal Victoria Yard, Deptford, from that very useful publication, ‘Chemistry, Theoretical, Practical, and Analytical,’ published by Mr W. Mackenzie.

“This stove consists of a brick chamber with a slightly arched roof, and an iron movable floor in two pieces. The chamber is 7 feet deep, 6 feet 9 inches wide, and 5 feet 8¹⁄₂ inches high in the centre of the arch. It is heated by a flue below the iron floor passing round 3 sides of the chamber and up a chimney. There is an opening in the upper part of the chamber in its centre, which passes along in the roof to the side, from thence down in the wall entering beneath the fire; this carries away any of the foul air of the clothes from the chamber through the fire and up the flue. This proceeding takes place after the clothes have been in the chamber say an hour and a half in the following manner:—The damper in the foul air shaft is withdrawn, and the furnace door is shut; any draught that gets to the fire comes to the chamber. Over the opening into the furnace is a square opening, fitted with a glass, inside of which is a fixed thermometer. When this shows a temperature of 200° F., the interior of the chamber is at 250° F., the highest point at which it is allowed to be. In the interior of the chamber at the sides there are little movable cranes, three rows of three supporting rods of iron on which wooden trays rest, and on which the clothes are placed when the iron cart is not used. The cranes move fore and aft to be out of the way when the cart is used. The cart is of iron on wheels, and runs into the chamber on tramways to keep it in position; in the interior of the cart are three iron trays for laying the clothes on. The lowest tray is always the hottest, so that it is prudent to use the cart, the iron bottom of which prevents burning. The iron ends of the cart are removed when it is placed in the chamber; so is the handle. It is usual to keep the clothes at the temperature of 250° F. for two hours.