100 ORD. XLVI. Liliacez. ALOE VULGARIS. 
IV. of this work: we have, therefore, a few observations only to make on 
the chemical properties of the hepatic, or Barbadoes aloes: which, as we 
have before observed, are the product of the aloé vulgaris. 
Hepatic aloes have a peculiar strong odour, somewhat aromatic, but less 
so than the Socotrine aloes. The taste is nauseous and intensely bitter. 
The pieces are of a dull brown colour, glossy, and when broken, the splin- 
" tered edges appear rather blunt, and of a dull yellowish hue. It becomes 
soft by the heat of the hand, and is adhesive ; when reduced to powder, it is 
of a dull yellow brown. All kinds of aloes yield a small portion of vegetable 
mucus, resin, and a peculiar extractive matter. Braconnot* found aloes to 
consist chiefly of a peculiar bitter matter, which he has termed the resinous 
bitter principle (dmer résineua).+ The odour, taste, and medical virtues of 
aloes, reside chiefly in the extractive. Boiling water dissolves nearly the 
whole of any of the kinds, but least of the hepatic or Barbadoes. | Proof- 
spirit takes up 86 parts in 100; the alkalies and their carbonates greatly as- 
sist in promoting the solution of aloes. _ By boiling aloes in water, the ex- 
tractive is altered, and rendered insoluble in water, and approaches to the 
nature ofa resin. _ Socotrine aloes yield, upon distillation, a small portion 
of volatile oil; but none is obtained from the hepatic. 
* Annales de Chimie, lv. 152. 
+ According to the analysis of Vogel, and Bouillon la Grange, aloes contain 32 parts 
resin, and 68 extractive. 
t This circumstance forms a test, which iectctahe hepatic aloes from the other 
ahs andependantly. of sensible properties, 
