I

16

Materia Medica.

Part II.

same medical properties as the socotorine. Barbadoes aloesis not so clear and bright as the foregoing sort; it is also of adarker colour, more compact texture, and for the most partdrier, though not so brittle. Its smell is much stronger andmore disagreeable ; the taste intensely bitter and nauseous,with little or nothing of the aromatic flavour of the socotorine.The best hepatic aloes from Barbadoes is in large gourd shells,and an inferior sort of it, which is generally soft and clammy,is brought over in casks. In Barbadoes the plant is pulledup by the roots, and carefully cleaned from the earth andother impurities. It is then sliced into small hand-baskets andnets, which are put into large iron boilers with water, andboiled for ten minutes, when they are taken out, and freshparcels supplied till the liquor is strong and black, which isthen strained into a deep vat, narrow at bottom, where it isleft to cool and to deposite its feculent parts. Next day thedear liquor is drawn off by a cock, and again committed to alarge iron vessel. At first it is boiled briskly, but towards theend it is slowly evaporated, and requires constant stirring toprevent burning. When it becomes of the consistence ofhoney, it is poured into gourds or calabashes for sale, andhardens by age. Barbadoes aloes is extremely apt to inducehaemorrhoids ; but it is generally preferred, because it is verydifficult to adulterate it without altering its appearance.

Fetid, Caballike, or Horse Aloes.

This sort is easily distinguished from boththeforegoingkindsby its strong rank smell; although, in other respects, it agreespretty much with the hepatic, and is not unfrequently sold inits stead. Sometimes the caballine aloes is prepared so pureand bright, as not to be distinguishable by the eye even fromthe socotorine ; but its offensive smell, of which it cannot bedivested, readily betrays it. Its fracture also resembles that ofcommon rosin, with which it is often adulterated, whereasthe fracture of socotorine aloes is unequal and irregular.

From sixteen ounces of aloes, Neumann extracted near fif-teen by means of alcohol. From the residuum water took upone drachm, about an ounce of impurities being left; on in-verting the procedure, and applying water first, he obtainedbut thirteen ounces and a half of watery extract, and from theresiduum alcohol dissolved an ounce and a half. According tothis analysis, 1000 parts of aloes contain about 7.8 soluble inwater only, or analogous to gum, 94. soluble in alcohol only, orresinous matter, and 895 soluble both in alcohol and in wateror extractive. Tromsdorff makes them consist of 25 resin and75 extractive, and Lagrange of 32 resin and 86 extractive. Dr