This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Cassia Fisularis Pharm. Lond. & Edinb. Cassia fistula: a hard woody cylindrical pod, of a tree resembling the walnut, (cassia fistula alexandrina C. B. & Linn.) which grows spontaneously in Egypt and the warmer parts of the East Indies, and has been thence introduced into the West. The pods or canes are about an inch in diameter, and a foot or more in length; externally, of a dark brown colour, somewhat wrinkled, with a large seam running the whole length upon one side, and another less visible on the opposite one; internally, of a pale yellowish colour, divided by thin transverse woody plates into a number of little cells, containing each a flattish oval seed with a soft black pulp.
(a) Baglivi, Experimenta circa salivam, Opp. p. 426.
The pulp of caffia has a sweetish taste, followed by more or less of an ungrateful kind of acrimony. The caffia of the East Indies has a more agreeable sweetness, and less acrimony than that of the West; and hence the former is universally preferred: they may be distin-guished from one another by the eye; the oriental canes being smaller, smoother, and thinner-rinded, and their pulp of a deeper shining black colour, than the occidental. The lighter canes of either sort, and those in which the seeds rattle on being shaken, are generally rejected: in these, indeed, the pulp has become dry, but it does not necessarily follow that it is damaged: it loses nothing in drying but its aqueous humidity, and by this loss it should seem to be effectually secured from growing mouldy or four, inconveniences to which in its moist state it is very subject.
The pulp of caffia, whether moist or dry, dissolves both in water and in rectified spirit; readily in the former, slowly and difficultly in the latter, and not totally in either: the part which remains undissolved appears to be of little or no activity. It is usually extracted by boiling the bruised pods in water, and evaporating the drained solution to a due consistence: the exhaling vapour carries off nothing considerable of the caffia. As it is very apt to grow four in keeping, only small quantities should be prepared at a time.
Caffia, in doses of a few drams, is a gentle laxative; of good use in costive habits, in inflammatory cases where purgatives of the more acrid or irritating kind can have no place, and, as Geoffroy observes, in the painful tension of the belly which sometimes follows the imprudent use of antimonials. It is rarely given in such doses as to have the full effect of a cathartic; the quantity necessary for this purpose, an ounce and a half or two ounces, being apt to nauseate the stomach, and produce flatulencies and gripes, especially if the caffia is not of a very good kind: mild aromatics, and dilution with warm liquors, are the best correctives.
It is sometimes acuated with the stronger purgatives, or with the antimonial emetics; of which last it is said by some to diminish the activity so far, that four grains and a half of the tartarum emeticum may be taken, in a decoction of caffia, by those who can bear but one grain and a half of the antimonial preparation by itself(a). It is often joined also as an auxiliary to the milder purgatives, as crystals of tartar, tamarinds, and manna; and of these, particularly of the latter, it is supposed to in-crease the cathartic virtue: a mixture of four drams of caffia, and one and a half or two of manna, is said, by Vallifneri, to purge as much as twelve drams of caffia or thirty-two of manna by themselves. * In the shops are kept electuaries of this kind, composed of six ounces each of pulp of caffia and syrup of pale roses; and two ounces †, or one and a half ‡ of manna; with one ounce †, or one and a half ‡of pulp of tamarinds.
(a) Malouin, Chimie medicinale, part. iii. chap. 38.
It is observable, that during the use of caffia, the urine appears frequently of a green colour, and sometimes, where the quantities taken arc considerable, of a dark brown or blackish.