Chapter III: Their Form of Prescription (6)

Cloves are the unexpanded flowers, or flower-buds, of the clove tree, which are first obtained when the tree is six years old; they are gathered in October and November before they open, and when they are still green; and are dried in the sun, after having been exposed to smoke at a heat of 120°, till they assume a brown hue. It is a curious fact that the flowers when fully developed are quite inodorous, and that the real fruit is not in the least aromatic. QUALITIES. _Form_, that of a nail, consisting of a globular head, formed of the four petals of the corolla, and four leaves of the calyx not yet expanded; and a germen situated below nearly cylindrical, and scarcely an inch in length. _Odour_, strong, fragrant, and aromatic. _Taste_, acrid, aromatic and permanent. Benzoic acid has lately been discovered in them.

SOLUBILITY. Water extracts their odour, but little of their taste; alcohol and ether take up both completely. MEDICINAL USES. They are more stimulant than any of the other aromatics; they are sometimes given alone, but more generally as a corrigent to other medicines. OFFICINAL PREPARATIONS. _Infusum Caryophyllorum._ L. _Spir. Lavand. co._ D. (=B=) FRAUDS. The Dutch frequently mix the best cloves with those from which the oil has been drawn.

CARYOPHYLLORUM OLEUM. This essential oil, in consequence of the resinous matter which it holds in solution, has a specific gravity of 1·020, and consequently sinks in water. When the oil has a hot fiery taste, and a great depth of colour, it is adulterated. It is imported from the spice islands. On account of its stimulant properties, it is added to griping extracts, or used as a local application in the tooth-ache. Vauquelin obtained from the leaves of the _Agathophyllum ravensara_ an essential oil, in every respect similar to that of cloves; and I am informed by Dr. Davy that an oil exactly resembling in smell the oil of Cloves is procured in Ceylon from the leaf of the Cinnamon tree; but very little, if any, has ever been exported.

CASCARILLÆ CORTEX. L.D. Croton Eleutheria. E. (Croton Cascarilla.)

_Cascarilla Bark._

QUALITIES. _Form_, curled pieces, or rolled up into short quills; its fracture is smooth and close, of a dark brown colour; _Odour_, light and agreeable; when burning, it emits a smell resembling that of musk, which at once distinguishes it from all other barks. _Taste_, moderately bitter, with some aromatic warmth. CHEMICAL COMPOSITION. Mucilage, bitter extractive, resin, volatile oil, and a large proportion of woody fibre; neither _Cinchonia_ nor _Quina_ has hitherto been discovered in it. SOLUBILITY. Its active constituents are partially extracted by alcohol and water, and completely by proof spirit. MEDICINAL USES. Carminative and tonic; it is an excellent adjunct to cinchona, rendering it by its aromatic qualities more agreeable to the stomach, and increasing its powers. It is valuable in dyspepsia and flatulent cholic, in dysentery and diarrhœa, and in the gangrenous thrush peculiar to children. FORMS OF EXHIBITION. It is most efficacious in substance; it may however be given in the form of infusion, or tincture. Decoction dissipates its aromatic principle; the extract therefore merely acts as a simple bitter. See _Infus. Cascarillæ_. DOSE of the powder, grs. xij to ʒss. OFFICINAL PREPARATIONS. _Infus. Cascarill._ L. _Tinct. Cascarill._ L.D. _Extract. Cascarill._ D.

CASSIÆ PULPA. L.E.D. Cassia Pulp. (Cassia Fistula, _Lomentorum Pulpa._)

The fruit is a cylindrical pod scarcely an inch in diameter, but a foot or more in length; the exterior is a hard brown bark; the interior is divided into numerous transverse cells, each of which contains an oval seed imbedded in a soft black pulp. QUALITIES. _Odour_, faint and rather sickly. _Taste_, sweet and mucilaginous. SOLUBILITY. Nearly the whole of the pulp is dissolved by water, partially by alcohol and sulphuric ether. CHEMICAL COMPOSITION. Sugar, gelatine, glutine, gum, and a small portion of resin, extractive, and some colouring matter. USES. It is gently laxative, and is adapted for children and very delicate women, but it should be always given in combination with manna or some other laxative, or it is apt to induce nausea, flatulence and griping. OFFICINAL PREPARATIONS. _Confectio Cassiæ._ L.E.D. _Confectio Sennæ_ (=B.O.=) L.E.D.[453] There are two kinds of this drug in the market; that from the West Indies, the pods of which are generally large, rough, thick rinded, and contain a nauseous pulp; and that from the East Indies, which is to be preferred, and which is distinguished by smaller and smoother pods, and by their containing a much blacker pulp. The pulp ought not to have a harsh flavour, which arises from the fruit having been gathered before it was ripe, nor ought it to be sour, which it is very apt to become by keeping. The heaviest pods, and those in which the seeds do not rattle, are to be preferred.

CASTOREUM. L.E.D. _Castor._ (Castor Fiber. (_Rossicus._) _Concretum sui
generis._)

This substance is secreted by the beaver, in bags near the rectum.[454] QUALITIES. _Odour_, strong and aromatic. _Taste_, bitter, sub-acrid, and nauseous. _Colour_, reddish brown. CHEMICAL COMPOSITION. Volatile oil, resin, mucilage, extractive, iron, and small portions of the carbonate of potass, lime and ammonia. It contains also, according to the analysis of Laugier, a small quantity of Benzoic acid. The Canadian variety is also stated by Laugier to contain benzoic acid both free and combined. SOLUBILITY. Its active matter is dissolved by alcohol, proof spirit, and partially by water; the tincture made with alcohol is the least nauseous, and the most efficacious; the spirit of ammonia is also an excellent menstruum, and in many cases improves its virtues. FORMS OF EXHIBITION. It may be given in substance, as a bolus, or in the form of tincture, but its exhibition in the form of extract or decoction is chemically incorrect. DOSE, grs. x to ℈j, and, in clysters, to ʒj. MEDICINAL USES. It is antispasmodic, and seems to act more particularly on the uterine system. It certainly proves beneficial as an adjunct to antihysteric combinations; it was highly esteemed by Van Swieten, De Haen, and many other German practitioners. Baglivi states that it counteracts the narcotic powers of opium, but this is not the case. OFFICINAL PREPARATIONS. _Tinct. Castorei_.[455] L.E.D. ADULTER: It is sometimes counterfeited by a mixture of dried blood, gum ammoniacum, and a little real castor, stuffed into the scrotum of a goat; the fraud is detected by comparing the smell and taste with those of real castor; and by the deficiency of the subaceous follicles, which are always attached to genuine specimens. There are two kinds in the market, the Russian and Canadian, the former however, which is the best, has become extremely scarce; it may be distinguished from the latter, by being larger, rounder, heavier, and less corrugated on the outside.

CATECHU EXTRACTUM, L.E.D.

(Acacia Catechu, _Extractum_.)

_Catechu_; olim _Terra Japonica_.[456] _Japan Earth._

QUALITIES. There are two varieties of catechu in the market, the one of a light yellowish, the other of a chocolate colour; they differ only in the latter having a more austere and bitter taste. CHEMICAL COMPOSITION. Tannin, a peculiar extractive matter, mucilage, and earthy impurities. SOLUBILITY. It is almost totally dissolved both by water and spirit. INCOMPATIBLE SUBSTANCES. Its astringency is destroyed by alkaline salts; and precipitates are produced by metallic salts, especially by those of iron; and with gelatine it forms an insoluble compound. MEDICINAL USES. It is a most valuable astringent. FORMS OF EXHIBITION. In infusion, tincture, or powder. (_Form. 51, 52, 58, 151._) In the form of a lozenge, from its gradual solution, it may be very advantageously applied in relaxed states of the uvula and fauces; I have found this remedy successful in cases where the _sulphate of zinc_ was inefficient. From its great astringency it also forms an excellent dentifrice, especially when the gums are spongy; for this purpose I have employed equal parts of powdered catechu, and Peruvian bark, with one-fourth the quantity of the powder of myrrh. DOSE, grs. x to ℈i. OFFICINAL PREP. _Infus. Catechu_, _Tinct. Catechu_, L.E.D. _Electuarium Mimosæ Catechu_, E.D.

CENTAURII CACUMINA. L.E.D.

(Chironia Centaurium[457] _Cacumina._)

_The flowering tops of the common Centaury._

QUALITIES. _Odour_, none; _Taste_, intensely bitter. CHEMICAL COMPOSITION. Mucilage, resin, and bitter matter. SOLUBILITY. Alcohol and water dissolve all its active matter. MEDICINAL USES. All its value depends upon its bitterness. It entered into the composition of the once celebrated _Portland Powder_ for the gout, for an account of which see page 32. DOSE, of an infusion, made in the proportion of ℥j to oj of boiling water, f℥ij; of the dry powder ʒi.

CERA. L.E.D. _Wax._

It is admitted into the list of the Materia Medica under two forms, viz.

1. CERA FLAVA. _Yellow or Unbleached Wax._

QUALITIES. _Odour_, faintly honey-like; it is brittle yet soft; when chewed, it does not, if pure, adhere to the teeth; it melts at 142°, and burns entirely away. CHEMICAL COMPOSITION. It is the honey-comb of the bee melted with boiling water, pressed through cloth bags, and ultimately cast into round cakes for the market. Whether it be an animal product, or a vegetable substance merely collected by the bee, has been a question of dispute; the former opinion is probably correct, although wax is certainly produced as a secretion by many plants. The yellow wax contains a portion of pollen which imparts its colour to it, and increases its fusibility. SOLUBILITY. It is insoluble in water, and in cold alcohol or ether, but it is soluble in boiling alcohol and ether, in fixed oils, and in alkalies. USES. It is chiefly employed in the composition of external applications. ADULTERATIONS. _Earth_ or _peas-meal_ may be suspected when the cake is very brittle, and the colour inclines to grey; _Resin_ is detected by putting it in cold alcohol, which will dissolve the resinous part without acting on the wax. _Tallow_ is discovered by the greater softness and unctuosity of the cake, and by its suffocating smell when melted; when this latter substance is employed, turmeric is added to disguise its paleness.

2. CERA ALBA. _White, Bleached, or Virgin’s Wax._

QUALITIES. This substance differs only from the former, in being colourless, harder, heavier, and less fusible. USES. It is said to be demulcent, and very useful in dysentery, but it is rarely used. FORMS OF EXHIBITION. It may be formed into a mixture by melting it with one-third of its weight of soap, and then gradually adding to it any mucilaginous liquid. ADULTERATIONS. _White Lead_ may be detected by melting the wax in water, when the oxide will fall to the bottom of the vessel; _tallow_ may be suspected when the cake wants its usual translucency.

CERATA. L.E. Cerates.

These compositions are characterized by a degree of consistence, intermediate between that of plasters, and that of ointments. As this consistence is obtained from the wax which they contain, they very properly derive from that substance the generic appellation of _Cerates_.

CERATUM CALAMINÆ. L. (_Ceratum lapidis Calaminaris._ P.L. 1787. _Ceratum epuloticum. P.L._ 1745). Ceratum Carbonatis Zinci Impuri. E. Unguentum Calaminare. D.—These preparations have been long known under the name of _Turner’s Cerate_; they form the basis of many extemporaneous cerates, in some of which nitric oxide of mercury, in the proportion of ʒj of the oxide to ℥j of cerate, and in others, the liquor of sub-acetate of lead, are introduced. By the former combination we obtain a very useful application to indolent and ill-conditioned ulcers, a valuable stimulant for inducing an action conducive to the regeneration of parts. By the latter combination we derive a remedy highly extolled by our most experienced surgeons, in the cure of burns and scalds.

CERATUM CANTHARIDIS. L. The basis of this preparation is spermaceti cerate _six parts_, to which is added, of powdered flies _one part:_ as it is intended to promote a purulent discharge from a blistered surface, it may be reduced in strength according to circumstances.

CERATUM CETACEI. L. (_Ceratum Spermatis ceti. P.L._ 1787. Ceratum Album, P.L. 1745). Ceratum Simplex. E. It furnishes a soft and cooling dressing, and constitutes a convenient basis for more active combinations, as in the following instance.

CERATUM PLUMBI ACETATIS. L. (_Unguentum Cerussæ Acetatæ, P.L._ 1787.) This is cooling for burns, excoriations, and inflamed surfaces.

CERATUM PLUMBI COMPOSITUM. L. (_Cerat: Lithargyri acetati compositum. P.L._ 1787.) This is “_Goulard’s Cerate_” and is applicable to the same cases as the former cerate; the camphor which enters into its composition imparts a gently stimulating power to it; it proves extremely serviceable in chronic opthalmia of the tarsus, and for the increased secretion of tears, which so frequently affects the eyes of persons advanced in years.

CERATUM RESINÆ. L. (_Ceratum resinæ flavæ, P.L._ 1787. _Ceratum citrinum._ 1745. _Yellow Basilicon_). Unguent: Resinosum, E. Unguent: Resinæ albæ. D. It is stimulant, digestive, and cleansing, and affords a very excellent application for foul and indolent ulcers.

CERATUM SABINÆ. L. _Savine Cerate._ It is intended to keep up a purulent discharge from a blistered surface; in practice however it is often found to fail from the difficulty of obtaining it good, since the acrid principle of the plant is injured by long boiling, and by being previously dried; the ointment also loses its virtue by exposure to the air.

CERATUM SAPONIS. L. This preparation was much used and recommended by the late Mr. Pott; in preparing it the greatest possible caution is required; the fire should never be too rapidly applied, the stirring should be uniform and incessant, and the heat should only be sufficient to keep the two compositions liquid at the time when they are united. The original intention of the cerate was to afford, when spread upon linen, a mechanical support to fractured limbs, and to keep the points of the bone in due apposition, while in consequence of the _acetate of lead_ which is formed in the first stage of the process for its preparation, it possesses the virtues of a saturnine dressing. As a mechanical agent it may prove at once effectual and dangerous, for if it be applied before all inflammation and swelling have entirely disappeared, the inflamed vessels may be completely strangulated by its unrelenting pressure, and high erysipelatous inflammation, and a rapid state of gangrene may be the result.

CERATUM SIMPLEX. A useful application to excoriations and sores.

Besides the above cerates, there are many magistral[458] preparations, of great practical value, and I must refer the surgical student for an account of them to that very useful little manual, entitled “_Pharmacopœia Chirurgica_.”

CETACEUM. L.

(Physeter Macrocephalus, _Concretum sui generis_.)

Spermaceti. E.D.

QUALITIES. _Form_, flakes, which are unctuous, friable, and white. _Odour_ and _taste_, scarcely perceptible. _Sp. Grav._ 9·433. It melts at 112°. CHEMICAL COMPOSITION. It is a peculiar modification of fatty matter. SOLUBILITY. It is insoluble in water and cold alcohol, but soluble in hot alcohol, ether, and oil of turpentine, but it concretes again as the fluids cool; in the fixed oils it is completely soluble. The alkaline carbonates do not affect it, but it is partially dissolved in the pure alkalies, and with hot ammonia it forms an emulsion which is not decomposed on cooling. USES. It is demulcent and emollient, but it possesses no advantages over the bland oils. FORMS OF EXHIBITION. It may be suspended in water by means of mucilage or yolk of egg. (_Formulæ 76, 78, 79._) OFFICINAL PREPARATIONS. _Ceratum Simplex_. E. _Ceratum Cetacei_. L. _Unguent. Cetacei_. L.D. From exposure to hot air, it becomes rancid; but it may be again purified, by being washed in a warm solution of potass.

CINCHONA. L.E.D. _Bark._ _Peruvian Bark._

_Jesuit’s Bark._

Notwithstanding the labours of the Spanish botanists, the history of this important genus is still involved in considerable perplexity, and owing to the mixture of the barks of several species,[459] and their importation into Europe under one common name, it is extremely difficult to reconcile the contradictory opinions which exist upon the subject, nor indeed would such an investigation be consistent with the plan and objects of this work. Under the trivial name _officinalis_, Linnæus confounded no less than four distinct species of cinchona, and under the same denomination the British Pharmacopœias, for a long period, placed as varieties the three barks known in the shops; this error indeed is still maintained in the Dublin Pharmacopœias, but the London and Edinburgh colleges have at length adopted the arrangement of Mutis, a celebrated botanist, who has resided in South America, and held the official situation of Director of the exportation of bark for nearly forty years.

CINCHONÆ CORDIFOLIÆ CORTEX. L.E. Cortex Peruvianus. D. Heart-leaved Cinchona Bark, commonly called _Yellow_ Bark.

CINCHONÆ LANCIFOLIÆ CORTEX. L.E. Cortex Peruvianus. D. Lance-leaved Cinchona Bark, common _Quilled_ bark—_Pale_ bark.

CINCHONÆ OBLONGIFOLIÆ CORTEX. L.E. Cortex Peruvianus. D. Oblong-leaved Cinchona Bark, called _Red_ bark.

QUALITIES. The _odour_ and _taste_ of these three species are essentially the same, although they differ in intensity. They are all bitter, sub-astringent and aromatic, but the flavour of the _Yellow_ bark is incomparably the most bitter, although less austere and astringent, whilst the red bark has a taste much less bitter, but more austere and nauseous than either of the other species. CHEMICAL COMPOSITION. Few vegetable substances have been more frequently, or more ably submitted to chemical analysis than the Peruvian bark, and yet but few results of any great practical utility had been obtained previous to the recent experiments of Pelletier and Caventou, communicated to the Academy of Sciences at Paris, since the publication of the fourth edition of the present work.

Dr. Maton[460] had several years ago observed, that an infusion of nutgalls produced a precipitate with the decoctions of Bark; a fact which necessarily produced considerable speculation. Seguin was induced to regard it as arising from the presence of _gelatine_, (_see p. 56_,) an opinion which Dr. Duncan proved to be erroneous, and shewed that it depended upon a new proximate principle, to which M. Gomez of Lisbon had previously assigned the name of _Cinchonine_. Besides which, bark was considered as containing resin, extractive, gluten, tannin, a small portion of volatile oil, and some salts with a base of lime; one of which however had been only found in _Yellow_ bark, and had been discovered to contain a peculiar vegetable acid, denominated by Vauquelin _Kinic_, a name which Dr. Duncan very judiciously superseded by that of _Cinchonic_ acid.

In the _Red_ bark, Fourcroy detected also a portion of citric acid, some muriate of ammonia, and muriate of lime. Upon which of these principles the tonic and febrifuge virtues of bark depends, has ever proved a fruitful source of controversy. Deschamps attributed them to _Cinchonate of Lime_, and asserted that two doses of thirty-six grains each, would cure any intermittent. Westering considered _Tannin_ as the active constituent; while M. Seguin assigned all the virtues to the principle which precipitates gallic acid, and which, as it has been before stated, he mistook for gelatine. Fabroni concluded from his experiments, that the febrifuge power of the bark did not belong exclusively and essentially to the astringent, bitter, or to any other individual principle, since the quantity of these would necessarily be increased by long boiling, whereas the virtues of the bark are notoriously diminished by protracted ebullition. This argument however will not go far, when we consider the chemical changes which the liquid is known to suffer during that operation, and by which a considerable portion of its matter is rendered insoluble. Such was the state of our knowledge respecting the composition of the _Cinchona_, when Pelletier and Caventou, guided by analogy, were led to infer the presence of an alkaline element of activity in its composition. The merit, belonging to the researches of these eminent chemists, does not so much consist in the discovery of new elements, as in the proofs which they have furnished of the well known principle, _Cinchonine_, being a salifiable base,[461] and in demonstrating the peculiar states of combination in which it exists in the different species of Cinchona.

1. _Cinchona Lancifolia._

Their analysis of the _Pale Bark_, furnished the following principles.

1. _Acidulous Kinate of Cinchonia._[462]

2. _A green fatty matter._

3. _Red Colouring matter, slightly soluble._

4. _Ditto soluble._ (Tannin.)

5. _Yellow colouring matter._

6. _Kinate of Lime._

7. _Gum._

8. _Starch._

9. _Lignin._

_Cinchonia_, when obtained in an isolated form,[463] is distinguished by the following characters and habitudes.

It is white, transparent, and crystallizes in the form of needles; it has but little taste, circumstance depending upon its comparative insolubility, as it requires no less than 7000 parts of cold water for its solution; in boiling water it is soluble in 2500 times its weight, but a considerable part separates, on cooling. In alcohol and the acids it is much more soluble, and imparts to such menstrua the characteristic bitter of the bark; it dissolves only in small quantities in the fixed and volatile oils, or in sulphuric ether. Cinchonia restores the colour of litmus which has been reddened by an acid. With acids it combines and forms neutral salts, of which the solubility and crystalline form vary with the acid employed.

_Sulphate of Cinchonia_, easily crystallizable and moderately soluble, has been found to consist of _Cinchonia_ 100, _Sulphuric acid_ 13·02.

_Nitrate of Cinchonia_, uncrystallizable, and sparingly soluble.

_Muriate of Cinchonia_, crystallizes in very beautiful needles, and is more soluble than the preceding salts.

_Oxalate of Cinchonia_, nearly insoluble; hence by pouring oxalic acid, or oxalate of ammonia into solutions of any of the soluble salts of cinchonia, we obtain a very white and abundant precipitate, which might be mistaken for oxalate of lime; it is however soluble in an excess of acid, and in alcohol.

_Gallate of Cinchonia_, equally as insoluble as the _Oxalate_, whence the precipitate occasioned by pouring an infusion of galls into the decoctions of genuine cinchona.

Cinchonia, when heated, does not fuse before decomposition. Its ultimate elements are _oxygen_, _hydrogen_, and _carbon_; the latter being predominant.

The _Kinic acid_, which exists in native combination with the _Cinchonia_, amongst several other peculiar properties, is convertible by means of heat into a substance (_acide pyrokinique_,) which is crystallizable, and capable of producing with iron a most beautiful green colour.

2. _Cinchona Cordifolia._

In the _Yellow Bark_, these chemists discovered also a salifiable base, quite distinct however in its character and habitudes from _Cinchonia_; they accordingly have designated it by another name, viz. _Quinine_, but which we shall hereafter call _Quina_. In speaking of these two bases, the authors compare them, in point of dissimilarity, to the fixed alkalies, potass and soda. _Quina_ is distinguished from _Cinchonia_ by the following characters. It cannot, like this latter body, be crystallized by evaporation from its alcoholic solution, although it may be obtained in transparent plates. _It is very soluble in æther_; in water it is as insoluble as cinchonia, but its taste is much more bitter. The salts which it forms are different from those of cinchonia, both in the proportion of their elements, and in the properties which they possess, being generally much more bitter. In comparing their composition, _Quina_ will appear to have less capacity of saturation[464] than cinchonia.

_Sulphate of Quina._ It forms crystals quite remarkable for their satin-like and pearly lustre. It is soluble in cold water, a property which is very considerably increased by an excess of acid.[465] It appears from the observations of M. Callaude, apothecary at Annecy, that _Sulphate of Quina_ exposed to a gentle heat, becomes highly luminous; and M. Pelletier has since found that _Sulphate of Cinchonia_, when exposed in a capsule to the steam of boiling water, exhibits the same phenomenon, but that neither _Quina_ nor _Cinchonia_, by themselves, nor their acetates, possess this phosphorescent quality. This appears to be the most efficient of all the salts of Bark, and is the one from which I have frequently derived much advantage. In its exhibition we must be careful not to combine it with substances that form insoluble compounds with it. The _Infusum Rosæ compositum_ is objectionable as a vehicle, on account of the astringent matter which it contains, and which therefore precipitates the _Quina_ from its solution. I have lately seen a prescription, in which the salt is directed to be rubbed with a few grains of _Cream of Tartar_, and then to be dissolved in mint water. This is obviously injudicious, since Tartaric acid decomposes the sulphate, and occasions an insoluble _Tartrate_, which is precipitated. The form in which I have usually prescribed it is in that of solution, with a small quantity of sulphuric acid, in the proportion of a minim to every grain of the salt. A _Wine of Quina_ may be made by adding five grains of the sulphate to a pint of Sherry; a Tincture, by dissolving the same quantity in eight fluid-ounces of Rectified Spirit. The sulphate is to be preferred to the pure _Quina_ in these cases, because, when the tincture is made by using the alkali, not saturated by an acid, a precipitate is formed on adding it to aqueous liquors. Dose of the Sulphate, gr. i.–v.

_Acetate of Quina_, very remarkable for the great facility with which it crystallizes, and for the pearly aspect and agreeable stellated grouping of the crystals; whereas the acetate of cinchonia crystallizes with difficulty, and simply in plates transparent, and devoid of lustre.

_Quina_ forms with the oxalic, gallic and tartaric acids, salts as insoluble as those which the same acids form with _Cinchonia_.

3. _Cinchona Oblongifolia._

The _Red Bark_ upon analysis was found to contain a double basis, and to yield both _Cinchonia_ and _Quina_, and, what is still more extraordinary, the quantity of each exceeded that which is known to exist in the _grey_ and yellow _barks_.

The latest experiments, however, made on very large quantities of the bark, have shewn that _Quina_ and _Cinchonia_ exist simultaneously in all the three species; but the _Cinchonia_ is, relatively to the _Quina_, in greater quantity in the _grey_ bark; whilst, in the _yellow_ bark, the _Quina_ so predominates, that the presence of the _Cinchonia_ might well have escaped notice when small quantities were operated on.

Having thus furnished a sketch of this curious discovery, we have next to enquire whether the alkaline bases in question do actually concentrate all the virtues of the barks in which they reside? M. Majendie[466] informs us that Pelletier had very early after the discovery transmitted to him a portion of the new substances for trial, and that he has unequivocally determined that they do not possess any deleterious qualities,[467] and are therefore essentially different from the principles of _Nux vomica_, (_Strychnine_,) Opium, (_Morphia_,) &c. According to the testimony of Dr. Double, as related in the same journal, they would seem to possess the medicinal properties of the cinchona.

In the third number of _Majendie’s Journal_ we receive a report from M. le docteur Renauldin, of an intermittent cured by the _Sulphate of Cinchonia_, in doses of six grains.

As the discovery of an alkaline element in Opium led the way to the detection of salifiable bases in other active vegetables,[468] it has seemed to me preferable that I should introduce those general observations which I wish to offer upon the subject of those bodies, under the history of that narcotic. It is only necessary in this place to caution the practitioner against the hasty generalizations of the too sanguine chemist; it has already been observed that those vegetable remedies, whose value has been established by the sober experience of ages, consist of different principles of activity, or, at least, owe a modified power to the compound effect of their several ingredients. (_p. 154, note._)

SOLUBILITY OF THE BARK.[469] Cold water extracts its bitter taste, with some share of its odour; when assisted by a moderate heat, the infusion is stronger, but becomes turbid as it cools; the infusion cannot be kept, even for a short time, without undergoing decomposition, and being spoiled; wine also extracts the virtues of bark, and is prevented by this substance from becoming sour, a fact which probably depends upon the avidity with which some of the principles of bark combine with oxygen, and which may throw some light upon the cause of its antiseptic virtues. The colouring matter of wine is precipitated by bark, as it is by charcoal, in the course of a few days. By decoction the active matter of cinchona is in a great degree extracted, but if the process be protracted beyond eight or ten minutes, it undergoes a very important chemical change, the precise nature of which is not well understood; the balance of affinities, however, by which the different elements are united, is evidently overthrown, and a considerable precipitation ensues; oxygen would also appear to have been absorbed; whether the _Cinchonia_ becomes insoluble has not yet been ascertained, but experience has shewn that the general loss of solubility, produced by such a process, is accompanied with a corresponding loss of medicinal activity; on which account, the extract is necessarily a very inefficient preparation; if we attempt to redissolve it, not more than one half is soluble in water. Vinegar is a less powerful solvent than water; the active matter of bark is rendered more soluble by the addition of mineral acids, and by the earths and alkalies; these latter bodies deepen its colour, and precipitate the _Cinchonia_, for which reason, when they are employed, the decoction ought not to be filtered; see _Form. 41, 42_, and note thereon. _Lime water_ has been recommended as a solvent, and it affords an excellent form for children and dyspeptic patients; for the same reason we obtain a stronger and perhaps a more efficient preparation, by triturating it with magnesia, previous to the process of infusion. Alcohol is a very powerful solvent, but the great activity of this menstruum so limits its dose that we are prevented from exhibiting a sufficient quantity of the bark in the form of tincture; it furnishes however an excellent adjunct to other preparations.

INCOMPATIBLE SUBSTANCES. Precipitates are produced by the _salts of iron_, _sulphate of zinc_, _nitrate of silver_, _oxy-muriate of mercury_, _tartarized antimony_, _solutions of arsenic_, _&c._ Any considerable portion of a tincture produces also a precipitation, which sometimes does not immediately take place, and the medicinal value of the bark is probably not impaired by it. As the infusions of _nut galls_ and some other vegetable astringents precipitate the cinchonia from bark, it becomes a question how far such liquids are medicinally compatible; saline additions, as _alum_, _muriate of ammonia_, _&c._ have been frequently proposed, but in many such mixtures decompositions arise which must deceive us with regard to the expected effects. FORMS OF EXHIBITION. No form is so efficient as that of powder, a fact which would seem to argue against the _exclusive_ value of the _Cinchonia_; even the ligneous fibre which the chemist pronounces to be inert and useless, may produce its share of benefit by modifying the solubility of the other ingredients, or by performing some mechanical duty which we are at present unable to understand or appreciate; but where the stomach rejects it, it must be administered in _infusion_ or _decoction_, with the addition of its _tincture_. In cases where it is necessary to join cordials, an infusion of bark in Port wine[470] is a popular and very useful form for its administration. DOSE of the powder, gr. v to ʒij or more, of the infusion or decoction ℥ij. MEDICINAL USES. It is powerfully tonic and antiseptic; it was introduced into practice for curing intermittent fevers, but since that period it has been generally used in diseases of debility, in fevers of the typhoid type, and in gangrene. It was first conjectured to be useful in gout by Sydenham, and Dr. Haygarth has strongly recommended its exhibition in acute rheumatism; when however it is used in these diseases, the greatest attention ought to be paid to the state of the bowels, and purgatives should be occasionally interposed. In Dyspepsia, the use of the purer bitters is to be greatly preferred to that of the bark. OFFICINAL PREPARATIONS. _Infus. Cinchonæ_, L.E.D. _Decoct. Cinchon._ L.E.D. _Extractum Cinchon._ L.E. _Extract. Cinchonæ resinosum._ L.D. _Tinct. Cinchonæ_, L.E.D. _Tinct. Cinchonæ comp._ L.E.D. _Tinct. Cinchon. Ammoniat._ L. MAGISTRAL FORMULÆ, 31, 37, 40, 44, 127. ADULTERATIONS. The frauds committed under this head are most extensive; it is not only mixed with inferior barks, but frequently with genuine bark, the active constituents of which have been entirely extracted by decoction with water. In selecting cinchona bark, the following precautions may be useful; it should be dense, heavy and dry, not musty, nor spoiled by moisture; a decoction made of it should have a reddish colour when warm; but when cold, it should become paler, and deposit a brownish red sediment. When the bark is of a dark _colour_ between red and yellow, it is either of a bad species, or it has not been well preserved. Its _taste_ should be bitter, with a slight acidity, but not nauseous, nor very astringent; when chewed, it should not appear in threads, nor of much length; the _odour_ is not very strong, but when bark has been well cured, it is always perceptible, and the stronger it is, provided it be pleasant, the better may the bark be considered. In order to give bark the form of _quill_, the bark gatherers not unfrequently call in the aid of artificial heat, by which its virtues are deteriorated; the fraud is detected by the colour being much darker, and upon splitting the bark, by the inside exhibiting stripes of a whitish sickly hue. In the form of powder, cinchona is always found more or less adulterated. During a late official inspection of the shops of apothecaries and druggists, the Censors repeatedly met with powdered cinchona having a harsh metallic taste, quite foreign to that which characterizes good bark.[471] The best test of the goodness of bark is afforded by the quantity of _Cinchonia_, or _Quina_ that may be extracted from it; and the manufacturer should always institute such a trial before he purchases any quantity, taking a certain number of pieces indiscriminately from the bulk. Much has been said of late concerning the probability of the genuine species of the cinchona tree becoming extinct; in consequence of which some succedaneum has been anxiously sought for; the bark of the broad-leaved willow, _Salix Caprea_, has been proposed for this purpose. Vogel recommends the root of _Geum urbanum avens_; others propose that of the _Dastisca canabina_.

The _Cinchona Caribæa_ of the Edinburgh Pharmacopœia is said, by Dr. Wright, to whom we are indebted for our knowledge of it, to have satisfactorily answered in all cases where the Peruvian bark was indicated. The _Geoffræa Intermis_ is often sold for it.