Chapter II: BLEACHING of =Linen=:--Linen may be bleached in a similar way to (25)

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, 5-1/2 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.= C_{6}H_{10}O_{5}. _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:--

[Footnote 257: 'Philosoph. Trans.' for 1861.]

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--

1 carat is worth £8
2 carats " £32
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= (fr[)a]m). 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.

=DIARRH[OE]'A.= A purging or looseness of the bowels. The causes of diarrh[oe]a 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 diarrh[oe]a 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 diarrh[oe]a arising from excessive peristaltic motion, or want of tonicity of the muscular coats of the intestines.

In bilious diarrh[oe]a, 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 diarrh[oe]a, chylous diarrh[oe]a, 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 diarrh[oe]a demands a nearly similar treatment.

The diet in every variety of diarrh[oe]a 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 diarrh[oe]a, 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.

Mean time of
chymification
Foods. How cooked. in stomach.
h. m.
Rice Boiled 1
Eggs, whipped Raw 1 30
Trout, salmon, fresh Boiled 1 30
Venison, steak Broiled 1 35
Sago Boiled 1 45
Milk Boiled 2
Eggs, fresh Raw 2
Milk Raw 2 15
Turkey Boiled 2 25
Gelatin Boiled 2 30
Goose, wild Roasted 2 30
Pig, sucking Roasted 2 30
Lamb, fresh Broiled 2 30
Beans, pod Boiled 2 30
Potatoes, Irish Baked 2 30
Chicken Fricassed 2 45
Oysters, fresh Raw 2 55
Eggs, fresh Soft-boiled 3
Beef, lean, rare Roasted 3
Mutton, fresh Boiled 3
Bread, corn Baked 3 15
Butter Melted 3 30
Cheese, old, strong Raw 3 30
Potatoes, Irish Boiled 3 30
Beef Fried 4
Veal, fresh Broiled 4
Fowls, domestic Roasted 4
Ducks, Domestic Roasted 4
Veal, fresh Fried 4 30
Pork, fat, and lean Roasted 5 15
Cabbage Boiled 4 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), 2-1/2 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 pharmacop[oe]ias.

=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: