61. Aloë, Linn.—Aloe, cont'd.

Continued from previous page.

Chemical Characteristics.—Aloes is almost completely soluble in boiling water. When the decoction of aloes cools, the substance called resin is deposited. The clear cold solution (aloesin) reddens litmus, strikes a deep olive-brown tint (aloesate of iron) with sesquichloride of iron, is deepened in colour by alkalies, but is unchanged with gelatine. Diacetate of lead forms a copious yellow precipitate with it.

The alcoholic tincture of aloes does not become turbid when mixed with water. When the ethereal tincture is poured in water, the ether evaporates, and leaves a film of resin.

The bitter principle of aloes [aloesin) is distinguished from that of rhubarb by its not striking a green colour with the salts of iron, and by its insolubility in ether.

The differential chemical characters of the various kinds of aloes are not constant. The following, however, are the results of some experiments:—

α. Cape aloes, when good, usually completely dissolves in boiling water, leaving no residuum of vegetable albumen, &c. The decoction is clear, usually paler than that of the other kinds, and deposits much of the so called resin in cooling.

β. Barbados aloes sometimes leaves an insoluble residuum (vegetable albumen, &c.) when boiled in water. The decoction, when cold, is dark and usually turbid: generally, it is darker than that of the other sorts, yet I have found it the palest. I have also observed that the decoction on cooling becomes turbid, and lets fall a yellow powder like that which I have seen in decoction of hepatic aloes.

γ. Socotrine aloes yields a decoction which, when cold, is dark and nearly clear.

δ. Hepatic aloes yields a decoction which, on cooling, frequently deposits a yellow powder.

Products of the decomposition of aloes by nitric acid.—When aloes is heated with nitric acid, nitrous fumes are evolved, and the principles of which aloes consist are oxidized. The residuum has an intensely bitter taste, and is termed artificial aloe- bitter (künstliches Aloebitter.) It is a mixture of several principles.

The products of the action of nitric acid on aloes have occupied the attention of several distinguished chemists; but the results of their experiments, though highly interesting, are not uniform. Braconnot [Ann. de Chimie, lxviii. 28.] and Chevreul [Ibid. lxxiii. 46.] examined the reaction. The former applied the term aloetic acid to the residual solid, which Liebig [Poggendorff's Annalen, xiii. 205; also, Liebig and Poggendorff's Handwörterbuch d. Chimie, S. 268, 1837.] subsequently declared to be a mixture of nitric or nitrous acid, carbazotic acid, and a peculiar, non-acid, resinous, red matter. Boutin [Journ. d. Pharmacie, t. xxvi. p. 185.] has more recently examined the reaction of nitric acid on aloes, and he states the products to be polychromatic acid (the aloetic acid of Braconnot) composed, according to Pelouze, of C15H2N2O13, oxalic acid, carbazotic acid, and cyanide. Schunk [Ann. der Chimie, Bd. xxxix.] states that, by the action of nitric acid on aloes, he obtained four peculiar acids, viz., aloetic acid, aloëresinic acid, chrysammic acid, C15HN2O12+HO, and chrysolepic add, C12H2N3O13+HO.

Mulder [Buchner's Repertorium, 3te Reihe, Bd. ii. 1849.] has recently examined the products of the reaction of nitric acid on aloes. Anhydrous-chrysammic acid, he says, consists of C14HN2O11. The so-called chrysolepic acid he considers to be identical with nitropicric acid (i. e. carbazotic acid). He found the composition of the foliaceous crystals of this acid to be C12H3N3O14.

Physiological Effects. α. On Vegetables.—Not ascertained.

β. On Animals.—Aloes is the ordinary purgative for solipedes (the horse, the ass, the zebra, &c.), as it is both safe and sure. In horses, previously prepared by two or three bran-mashes to soften the dung, the dose is from five to seven drachms. [Youatt, The Horse, p. 211.] It acts slowly, requiring from eighteen to forty-eight hours for its operation. [Moiroud, Pharm. Vétér. p. 26.] Mr. Youatt informs me that aloes is a valuable purgative for the dog, in doses of from one to three drachms, and with the addition of from one to three grains of calomel. Barbados aloes is preferred by veterinarians, as being more effective than Cape aloes, in the ratio of about seven to five. Aloes proves purgative to oxen, sheep, and pigs, but, as in the other cases, it operates slowly. [Wibmer's Wirk. d. Arzneim.] Moiroud [Op. cit.] injected into the veins of a horse four drachms of aloes dissolved in water with a little alcohol, and the next day an ounce more, without any other effect than the evacuation of a large quantity of urine. The dung, however, was enveloped by a thin pellicle formed by altered intestinal mucus. This was collected and analyzed subsequent to the death of the animal (which followed three days after the injection): it offered scarcely any traces of the constituents of the bile.

γ. On Man.—Taken internally in small doses aloes acts as a tonic to the alimentary canal, assisting the digestive process, strengthening the muscular fibres, and promoting the secretions, especially that of the liver, which organ it is thought specifically to influence. In large doses it acts as a purgative. There are, however, some peculiarities attending its cathartic operation deserving of notice. In the first place, these effects are not so speedily produced as by some other purgatives; for eight, twelve, and sometimes twenty-four hours elapse before they are produced. Secondly, aloes acts especially on the large intestines, and a full dose is in some persons apt to produce heat and irritation about the rectum, and tenesmus; and, in those troubled with hemorrhoids, it is said not unfrequently to increase, or even to bring on, the sanguineous discharge. Fallopius [Opera Omnia, p. 109, Francof. 1600.] tells us, that of one hundred persons who used aloes as a purgative, ninety were affected with the hemorrhoidal flux, which ceased when the use of aloes was omitted. But though this statement has been often quoted as an objection to the use of aloes, it is of little importance, as there is no evidence that the disease was brought on by aloes. The uterus, in common with all the pelvic viscera, is stimulated by aloes. A determination of blood towards these organs, and a fulness of the blood-vessels (especially of the veins), are produced, and thus uterine irritation and monorrhagia are apt to be increased by aloes, while in amenorrhoea and chlorosis it may occasionally act as an emmenagogue. Dr. Wedekind [Rust's Magazin, 1827, Bd. 24, Heft 2, S. 304.] says that small doses of aloes often occasion erection, and increase the sexual feelings.

The purgative effects of aloes do not arise merely from their local action on the alimentary canal, since this effect is sometimes produced when the medicine has been neither swallowed nor given by the rectum. Thus Monro primus [Works, p. 306, 1781.] tells us, that the tincture of aloes applied to a caries of the bone produced purging; and it is said [Mém. de la Soc. Roy. de Mèd. Paris, torm. ii. p. 162.] that an aloetic pill used as a stimulant to an issue had a similar effect; lastly, applied to a blistered surface it has the same operation. So that the purgative action of aloes appears to be of a specific kind.

According to Dr. Wedekind, [Op. cit.; also, Lancet, vol. i. p. 347, 1827-8.] the operation of aloes depends on the increased secretion of bile, which is produced by the specific action of this medicine on the liver. He founds this opinion on the results of various experiments. Thus, he says, that if aloes be added to purgatives (a laxative infusion and sulphate of soda), whose operation is speedy, its effects do not take place for some hours after those caused by the other purgatives; and he also asserts that the evacuations in the second purging differ from those of the first both in appearance and smell. Moreover, he found that, as long as the stools were white or gray in icterus, the aloes did not purge even when exhibited in large doses; but the purgative effect supervened immediately after the fecal matter began to contain bile, proving that the presence of bile in the intestinal canal is a necessary condition of the purgative effect of aloes. But in Moiroud's experiment, above quoted, no effect seemed to be produced on the hepatic secretion.

In all probability, the increased secretion of bile, the irritation about the rectum, the disposition to hemorrhoids, and the vascular excitement of the sexual organs, all of which are said to be produced by aloes, are the effects of a stimulant action exerted by this medicine over the venous system of the abdomen, and especially of the pelvis.

Dr. Greenhow [Lond. Med. Gaz. vol. xix. p. 270.] ascribes a diuretic effect to aloes, and his statement is corroborated by Moiroud's experiment.

Socotrine aloes is said not to be so apt to occasion hemorrhoids as the Barbados kind. Some years since, Dr. Clutterbuck instituted numerous experiments at the General Dispensary, Aldersgate Street, which I witnessed, to determine the effects of the different kinds of aloes, but scarcely any difference in their operation on the human subject was perceptible. However, it is probable that Cape aloes is less powerful in its action on man, as it is on the horse, than the Barbados kind. But the difference is the less obvious in the human subject, on account of the comparative smallness of the dose required to produce the purgative effect.

As a purgative, aloes holds an intermediate rank between rhubarb and senna. Vogt [Pharmakodynamik, Bd. ii. S. 334, 2te Aufl.] places it between jalap and rhubarb. From rhubarb it is distinguished by its more stimulant influence over the large intestines and the pelvic organs: from senna by its feebler action as a purgative, by its slow operation, and by its tonic influence when given in small doses. It irritates less powerfully than either jalap or scammony: further, its influence over the blood-vessels of the pelvic viscera is greater than these.

Use.—The uses of aloes may be readily inferred from the remarks already made. It is evidently not adapted for those cases in which a speedy effect is required; and it is, therefore, useless to add it to purgatives to quicken their operation. It is well fitted for cases of costiveness where there is a scanty secretion of bile, and for torpid conditions of the large intestines, especially when attended with deficient uterine action. Some of the ill effects ascribed to the use of aloes are probably imaginary, and others are much exaggerated. [On the Use and Abuse of Aloes, London Medical Gazette, vol. iv. p. 139.] It is, however, advisable to avoid the use of this purgative in inflammatory conditions and organic diseases of the liver, in biliary calculi, in mechanical impediments to the passage of the blood through the branches of the portal veins, in hemorrhage from any of the pelvic organs (as the uterus and rectum), in irritation of the rectum, prostate gland, or bladder, in pregnancy, &c. For we have many other equally efficient purgatives, to the use of which, in these cases, no ill consequences have been ascribed. While, therefore, I concur with Dr. Fothergill [Med. Obs. and Inq. vol. v. p. 173.] in advising that the exhibition of aloes should be avoided when the menses are about to cease, I am not prepared to admit that "the piles, strangury, immoderate discharges of the menses, racking pains in the loins, representing labour pains, and other similar complaints," are frequently induced by this medicine. On the contrary, I suspect this catalogue of the evils of aloetic purges to be much overcharged. "Aloetic medicines," says Dr. Denman, [Introd. to the Pract. of Midwifery.] "are forbidden during pregnancy, lest they should do mischief by their supposed deobstruent qualities; but they are cheap, and conveniently given in the form of pills, and I have not observed any bad effects from them." The emaciation, stricture of the rectum, and enteritis, referred by Dr. Greenhow [Lond. Med. Gaz. vol. xix. p. 270.] to the long-continued use of aloetic medicines, ought, doubtless, to be ascribed to other causes.

The following are some of the cases in which the use of aloes has been advised:—

1. In loss of appetite and dyspepsia, depending on a debilitated condition of the digestive organs, accompanied by costiveness, but unattended with any signs of local irritation, aloes may be given in small doses as a stomachic.

2. In habitual costiveness, depending on deficiency of bile, or on a sluggish condition of the large intestines—particularly in hypochondriacal or studious persons, or in those whose habits or occupations are sedentary—aloes, given in sufficient doses to purge, will be found a very useful medicine. A torpid state of the colon, with large fecal accumulation, is not unusual in females. [Copland, Dictionary of Practical Medicine, art. Colon, torpor of.] In such, the use of aloes is often attended with much benefit.

3. To excite the menstrual discharge, aloes is frequently employed. It has been supposed that, by determining an afflux of blood to the pelvic organs, aloes would stimulate the uterine vessels, and thus relieve deficient menstruation connected with atonic conditions of the uterus. But it often fails: indeed, Dr. Cullen [Treat. of the Mat. Med.] says that it rarely succeeds.

4. To reproduce the hemorrhoidal discharge, aloes has been frequently employed in large doses. Serious affections of the head, or of other parts, have sometimes disappeared on the occurrence of the hemorrhoidal flux; and, therefore, in persons who have been subject to this discharge, but in whom it has stopped, it is advisable to attempt its re-establishment, with the view of relieving other more serious disorders.

5. To promote the secretion of bile where a deficiency of this fluid does not arise from hepatic inflammation; as in some forms of jaundice which are unconnected with biliary calculi, inflammation, mechanical obstruction of the ducts, &c.

6. In cerebral affections.—The compound decoction of aloes is a most valuable stimulating purgative for elderly persons in whom a tendency to apoplexy exists, especially in cold and phlegmatic habits. It will frequently be necessary to conjoin other cathartics, as the infusion of senna.

7. As an anthelmintic, a decoction of aloes, used as an enema, has been efficacious in the small thread-worm (Ascaris vermicularis).

Administration.—On account of its nauseous taste, aloes is frequently given in the form of pill (pilulae aloeticae, offic). One or two grains seldom fail to produce one stool, which seems to be merely an evacuation of what may be supposed to have been present for the time in the great intestines (Cullen). The ordinary dose is five grains; but ten, fifteen, or even twenty grains are sometimes given.

1. PILULA ALOËS COMPOSITA, L. D.; Pilulae Aloës, E.; Compound Pills of Aloes.—(Socotrine Aloes [Hepatic, D.], powdered, ℥j; Extract of Gentian ℥ss; Oil of Caraway ♏xl. [fʒss, D.]; Treacle, as much as may be sufficient [℥ss, D.] L.; beat them together until incorporated. The Edinburgh College orders of Socotrine Aloes and Castile Soap equal parts; Conserve of Red Roses a sufficiency; beat them into a proper pill mass. This pill may be also correctly made with the finer qualities of East Indian Aloes, as the Socotrine variety is very scarce; and many, not without reason, prefer the stronger Barbados Aloes, E.)—This pill is a valuable purgative in habitual costiveness. Dose, five to fifteen grains.

2. PILULA ALOËS CUM MYRRHA, L. D.; Pilulae Aloës et Myrrhae, E. [U. S.]; Pilulae Rufi, offic.; Pills of Aloes and Myrrh; Rufus's Pills.—(Socotrine or Hepatic Aloes ℥ss [four parts, E.]; Saffron ʒj [one part, E.]; Myrrh ʒij [two parts, E.]; Soft Soap ʒij; Treacle [Conserve of Red Roses, E.], as much as may be sufficient. Rub the aloes and the myrrh separately to powder; then beat the whole together until incorporated [Aloes ℥ij; Myrrh ℥j; Saffron ℥ss; Syrup q. s. M. To be divided into 480 pills, U. S.]).—Used as a purgative in chlorosis and amenorrhoea. Dose, ten to twenty grains.

3. PILULA ALOËS CUM SAPONE, L.; Pilula Aloës diluta; Pills of Aloes and Soap.—(Extract of Barbados Aloes powdered, Soft Soap, Extract of Liquorice, equal parts; Treacle as much as may be sufficient. Beat the aloes with the soap; then, having added the others, beat the whole together until incorporated.)—Dose, grs. v to grs. x.

4. PILULAE ALOËS ET ASSAFOETIDAE, E. [U. S.]; Pills of Aloes and Assafetida.—(Aloes [Socotrine or East Indian], Assafetida, and Castile Soap, equal parts. Beat them, with Conserve of Red Roses, into a proper pill mass.)—Used in dyspepsia attended with flatulence and costiveness. Dose, ten to twenty grains.

5. PILULAE ALOËS ET FERRI, E.; Pills of Aloes and Iron.—(Sulphate of Iron three parts; Barbados Aloes two parts; Aromatic Powder six parts; Conserve of Red Roses eight parts. Pulverize the aloes and sulphate of iron separately; mix the whole ingredients, and beat them into a proper mass, which is to be divided into five-grain pills.)—A valuable emmenagogue in atonic amenorrhoea and chlorosis. Dose, one to three pills.

6. PULVIS ALOËS COMPOSITUS, L.; Compound Powder of Aloes.—(Socotrine or Hepatic Aloes ℥iss; Guaiacum Resin ℥j; Compound Powder of Cinnamon ℥ss. Rub the aloes and the guaiacum resin, separately, to powder; then mix them with the compound powder of cinnamon.)—Purgative and sudorific. Seldom used. Dose, ten to twenty grains.

7. PULVIS ALOËS CUM CANELLA [U.S.]; Hiera Picra, offic.; Powder of Aloes and Canella.—(Hepatic Aloes lb j; Canella bark ℥iij. Powder them separately, and then mix.)—A popular emmenagogue. Dose, five to fifteen grains.

8. DECOCTUM ALOËS COMPOSITUM, L. D.; Decoctum Aloës, E.; Compound Decoction of Aloes.—(Extract of Liquorice ʒvij [℥ss, E. D.]; Carbonate of Potash ʒj [℈ij, E. D.]; Extract of Socotrine Aloes [Hepatic, D., or Socotrine, E.] powdered, Myrrh powdered, Saffron, of each ʒiss [ʒj, E. D.]; Compound Tincture of Cardamom f℥vij [f℥iv, E., as much as is sufficient, D.]; Distilled Water Oiss [f℥xvj, E., f℥xiv, D.] Boil down the liquorice, carbonato of potash, aloes, myrrh, and saffron, with the water, to a pint [f℥iij, E.], and strain; then add the compound tincture of cardamom [as much as will make sixteen fluidounccs, D.]).—A most valuable preparation. A mild cathartic, tonic, antacid, and emmenagogue. Used in the before-mentioned cases in doses of f℥ss to f℥ii. Acids, acidulous salts, and most metallic salts, are incompatible with it. If it be desirable to conjoin chalybeates with it, either the Potasses Ferrico-Tartras (see vol. i. p. 752) or the Ammoniae Ferrico-Citras (see vol. i. p. 749) may be added to the cold decoction without undergoing decomposition. The quality of the aloes used, the length of time the decoction is boiled, and the purity of the extract of liquorice, affect the transparency or turbidity of this decoction, which is never so bright as tincture of aloes. [Pharmaceutical Journal, vol. i. p. 182, 1841.]

9. EXTRACTUM ALOËS, L.; Extractum Aloes Purificatum; Purified Extract of Aloes.—(Socotrine Aloes ℥xv; Boiling Water Cong. j. Macerate for three days with a gentle heat; afterwards strain and set by, that the dregs may subside. Pour off the clear liquor, and evaporate it to a proper consistence.)—It is intended to deprive the aloes of the substance called resin, on which its irritating and griping qualities have been supposed to depend. Dose, five to fifteen grains.

β. EXTRACTUM ALOËS BARBADENSIS, L.; Extract of Barbados Aloes.—This is prepared in the same way as the Extractum Aloës, L.

γ. EXTRACTUM ALOËS HEPATICAE; Extractum Aloes Aquosum, D.; Extract of Hepatic Aloes; Watery Extract of Aloes.—Hepatic Aloes, in coarse powder, ℥iv; Water Oij. Boil the aloes until it is dissolved; when the solution is cold, and the dregs have subsided, pour off the clear liquid, and evaporate it to a proper consistence, D.

The effects, uses, and doses of these two preparations are the same as those of Extractum Aloes.

10. TINCTURA ALOËS, L. E. [U. S.]; Tincture of Aloes.—(Socotrine or Hepatic Aloes, coarsely powdered, ℥j; Extract of Liquorice ℥iij; Distilled Water Oiss [Oj and f℥viij, E.]; Rectified Spirit Oss [f℥xij, E.]. Macerate for seven [with occasional agitation, E.] days, and strain. This tincture cannot without difficulty and delay be prepared by percolation, E.)—Purgative and stomachic. Dose, ʒij to ℥j.

11. TINCTURA ALOËS COMPOSITA, L.; Tinctura Aloes et Myrrhae, E. [U. S.]; Elixir Proprietatis of Paracelsus, Compound Tincture of Aloes.—(Socotrine or Hepatic Aloes, coarsely powdered, ℥iv [℥iij, U. S.]; Saffron ℥ij [℥i, U. S.]; Tincture of Myrrh Oij. Macerate for seven days, and strain, L. This tincture cannot be well prepared by percolation, E.)—Purgative, stomachic, emmenagogue. Used in cold, sluggish habits. Dose, ʒss to ʒj.

12. VINUM ALOËS, L. E. [U.S.]; Tinctura Sacra; Wine of Aloes.—(Socotrine or Hepatic Aloes, rubbed to powder, ℥ij; Canella, powdered, ʒiv; Sherry Wine Oij. Macerate for seven days, frequently shaking, and strain. The Edinburgh College uses Aloes [Socotrine or East Indian] ℥iss; Cardamom seeds ground, Ginger in coarse powder, of each ʒiss; Sherry Oij. Digest for seven days, and strain through linen or calico [Aloes, in powder, ℥i; Cardamom bruised, Ginger bruised, of each a drachm; White Wine a pint. Macerate for fourteen days, with occasional agitation, and filter through paper, U. S.]).—Wine of aloes is purgative in doses of f℥ss to f℥ij; stomachic in doses of fʒj to fʒij.

Aloes is a constituent of several other preparations (as Pilula Colocynthidis composita, L. D.; Pilulee Colocynthidis, E.; Pilulae Rhei compositae, L. E.; Pilulae Cambogiae, E.; Pilulae Cambogiae compositae, L.; Tinctura Rhei et Aloes, E.), which will be described hereafter.

The Elements of Materia Medica and Therapeutics, Vol. II, 3th American ed., was written by Jonathan Pereira in 1854.