This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Aloes: a bitter, gummy-resinous, infpif-fated juice; prepared from the leaves of certain thick fleshy-leaved plants of the same name. Three sorts of it are distinguished in the shops.
(a) Hift. des plantes aux environs de Paris. (b) Mater. Medic.\
1. Aloe Socotorina Pharm. Lond. Aloe-succotrina Ph. Edinb. Socotorine aloes; brought from the island Socotora in the Indian ocean, wrapt in skins; obtained from the Aloe socotrina angustifolia spinosa flore purpureo Breyn: a variety of the Aloe perfoliata Linn. This sort of aloes is of a bright surface, and in some degree pellucid; in the lump, of a yellowish red colour with a purplish cast; when reduced into powder, of a golden colour. It is hard and friable in the winter, somewhat pliable in the summer, and softens betwixt the fingers. Its bitter taste is accompanied with an aromatic flavour, but not sufficient to prevent its being disagreeable: the smell is not very unpleasant, and somewhat resembles that of myrrh.
2. Aloe barbadensis Ph. Lond. Aloe hepatica Pharm. Edinb. Hepatic, Barbadoes, or common aloes; usually brought from Barbadoes, the best sort in large gourd shells, an inferiour kind in pots, and a still worse in casks; extracted from the Aloe C. B. Aloe dioscoridis & aliorum. Sloan jamaic. This is darker coloured than the foregoing, and not so clear or bright. It is generally drier and more compact; though sometimes, especially the cask sort, quite soft and clammy. Its smell is much stronger and more disagreeable: the taste in-tensely bitter and nauseous, with little or nothing of the aromatic flavour of the focotorine.
3. Aloe caballina. Caballine or horse aloes; prepared, probably, from the aloe gui-neenfis caballina vulgari similis sed iota maculata Commel. praelud. not, as is generally supposed, the feces of the hepatic; the difference not being in purity, but in quality. It is easily distinguished from both the foregoing by its strong rank smell: in other respects it agrees pretty much with the hepatic, and is, not unfrequently, fold in its place. Sometimes it is prepared so pure and bright as scarce to be distinguishable by the eye even from the foco-torine, but its offensive smell readily betrays it; and if this also should be dissipated by art, its wanting the aromatic flavour of the finer aloes will be a sufficient criterion.
Aloes is a stimulating cathartic bitter. Taken in sufficient doses to purge effectually, as half a dram or two scruples, it occasions commonly a great irritation about the anus, and sometimes a discharge of blood. In smaller doses, as ten or twelve grains, repeated once or twice a day, it not only unloads the first passages, but attenuates and dissolves viscid humours in the remoter parts, warms the habit, quickens the circulation, and promotes the menstrual and haemorrhoidal fluxes: its continued use renders the blood sensibly more fluid, as appears on venefection. For a time, in these small doses, it does not act by stool; but at length it produces a gentle looseness, of longer continuance than that occasioned by most other purgatives: hence its utility in habitual costive-ness. This stimulating cathartic is particularly adapted to persons of a phlegmatic temperament and sedentary life, to cachectic indispositions, and oppressions of the stomach by viscid crudities contracted from irregularity: in dry bilious habits, it is often injurious, immoderately heating the blood, or inflaming the bowels.
This bitter juice is accounted destructive to worms, or to the matter which favours their production, whether taken internally, or applied in plasters to the umbilical region. It is powerfully antiseptic; and commonly made an ingredient in tinctures and balsams for cleansing and healing wounds or putrid fores.
Aloes consists of a resinous matter, and a large proportion of a substance called gum. By boiling in water, in the proportion for instance of four ounces to a quart, it nearly all dissolves, except the impurities, into a dark coloured liquor; which on standing in the cold for a night, deposites the resin to the bottom, the gummy part continuing dissolved. From this solution (poured off from the precipitated resin, and, if any feculencies appear in it, passed through a strainer) the gum may be recovered in a solid form by evaporation. The coarser sorts of aloes may be purified from their feculencies, without any separation of the gummy and resinous parts, by straining the solution whilst hot, and setting it directly to evaporate, without suffering it to fettle.
The hepatic aloes is found to contain more resin and less gum than the focotorine, and this than the caballine. Twelve ounces of ca-balline aloes yielded two of resin, the same quantity of focotorine three, of hepatic almost four: of gummy extract, the caballine yielded nine ounces, the focotorine somewhat less than nine, the hepatic eight. The watery solution of the gummy part of the focotorine, after the separation of the resin, appeared of a bright brown colour, with a cast of red; that of the caballine, deep reddish brown; of the hepatic, brownish yellow, without any tendency to redness.
The resins of all the forts, purified by solution in spirit of wine, (for in their fettling from the watery decoction of the aloes, the impurities of the juice subside along with them) have little smell; that obtained from the focotorine has scarcely any perceptible taste, that of the hepatic a flight bitterish relish, and that of the caballine a little more of the aloetic flavour. The gummy extracts also are less disagreeable than the crude aloes: the extract of the focotorine has very little smell, and is in taste scarcely unpleasant: that of the hepatic is in smell somewhat stronger, but seems to be in taste rather less ungrateful than the extract of the focotorine: the gum of the caballine retains a considerable share of the peculiar rank smell of this kind of aloes, but its taste is not much more unpleasant than that of the extracts made from the other two.
The purgative virtue of aloes, contrary to that of most of the other cathartic vegetables, resides chiefly in the gummy part; the resin, though taken in considerable doses, whether divided by testaceous powders, or dissolved in spirit of wine, having little or no cathartic power. Socotorine aloes, which contains more gum than the hepatic; purges more, and with greater irritation: the former therefore is to be preferred where a stimulus is required, as for promoting or exciting the menstrual flux; whilst the latter is better fitted for a common purge. The vulnerary and balsamic virtues, on the other hand, reside principally in the resin; and hence the hepatic, which is more resinous than the focotorine, is found to be more fer-viceable in external applications. The caballine aloes, on account of its offensive smell, is very rarely made use of, at least under its own name, either internally or externally.
The purgative aloetic gum dissolves, not only in watery, but likewise in spirituous menstrua; and even more readily in proof spirit and in rectified spirit, than in water or wine. When powdered aloes is macerated, or digested in a gentle warmth, with water, with wine, or with vinous spirits largely diluted, the powder sof-tens, and becomes tenacious, and the solution goes on exceeding slowly: hence in making tinctures or solutions of aloes in these kinds of menstrua, it is of advantage to mix with the powder some clean dry sand, which by keeping it divided, promotes the dissolution. With rectified and proof spirits, the aloes does not cohere, but continues powdery till dissolved.
Aloes is sometimes taken by itself, sometimes mixed with saponaceous medicines, warmed with aromatics, acuated with pungent materials, combined with the deobstruent gums, etc. Many of these kinds of compositions have been received as officinals: a pill, for example, com-posed of equal parts of aloes and extract of gentian, or half the proportion of the latter*: a powder, of eight parts of aloes, with two of canella alba †: a tincture, made by digesting five ounces of this powder in three ‡pints of mountain wine and one of proof spirit; or one ounce of aloes, with one dram each of Cardamom seeds and ginger, in two pounds of the same wine ||: another tincture of half an ounce of aloes and an ounce and a half of extract of liquorice in half a pint of proof spirit with as much water §: pills of four parts of aloes, two of myrrh, and two ¶ or one** of saffron, made up with syrup of saffron or of orange peel: vinous and spiri-tuous tinctures of the aloes with different proportions of the myrrh and saffron † & c. Among different aromatic materials made trial of, cloves seemed the best adapted for alleviating the offensiveness of the aloes: the committee appointed by the London college for reforming their pharmacopoeia, made choice of canella alba, on account of its not rendering the medicine so hot as the necessary quantity of the clove itself would do, and yet having so much of the clove flavour, as to cover the aloes in a sufficient degree: some commend the casia caryophyllata, or clove bark, as having more of the clove flavour, than canella alba, and yet not being very hot. - Where volatile spirits are to be joined, a solution of the aloes in dulcified spirit of sal ammoniac, or in spirit of sal ammoniac made with quicklime, are very elegant preparations, and require little assistance from aromatics to render them supportable to the palate; the offensiveness of the aloes being greatly abated by the spirit, and the pungency of the spirit sheathed by the aloes: the spirit of sal ammoniac made with fixt alkaline salt does not dissolve near so much of the aloes as the two above-mentioned.
* Pil. aloe-ticae Ph. Ed, Id. Ph. Lond. t Pulvis A-loeticus Ph. Load.
‡Vinum A-loes Ph. Lond. ||Tinct.Sacr. Ph. Ed.
§ Tinctura Aloes Ph. Lond.
¶ Pil. exAlo-ecum Myrrha Ph. Lond.
** Pil. communes vulgo Rusi Ph Ed.
Elixiria proprietatis varia