CRUDE DRUGS. 663 



usually, however, concentrated by boiling and then poured into 

 boxes or gourds, and occasionally it is found in commerce enclosed 

 in monkey-skins (Fig. 275). Socotrine aloes commands the high- 

 est price. The latter variety when fresh has an unpleasant odor, 

 but on keeping develops an odor resembling myrrh and saffron. 



1. Socotrine Aloes. In yellowish-brown to dark-brown 

 opaque masses, or smooth and glassy, fracture somewhat conch- 

 oidal ; odor saffron-like ; powder yellowish-brown or brownish- 

 yellow, giving a yellowish or reddish-brown color with nitric acid. 

 About 50 per cent, of socotrine aloes is soluble in cold water. 

 It is almost completely soluble in 60 per cent, alcohol or in water 

 at 100 C. On cooling the latter solution there separates from 

 40 to 60 per cent, of the so-called " resin of aloes," which is solu- 

 ble in alkalies with a red color and is reprecipitated on the addi- 

 tion of acids. About 36.6 per cent, of aloes is soluble in chloro- 

 form, and from 4 to 5.5 per cent, in ether, the solution being of a 

 yellow color. It should contain not more than 8 per cent, of 

 moisture and yield not more than 4 per cent, of ash. 



Zanzib.\r Aloes is a hepatic (or liver-colored) variety of 

 Socotrine Aloes, produced by slowly evaporating the juice of the 

 plant. It comes into market frequently in monkey-skins, has a 

 dark brown color, a dull, waxy fracture, and a nearly smooth, 

 even surface. It is crystalline under the microscope and forms a 

 reddish-yellow powder that is colored dark yellow with nitric acid. 



2. Curasao Aloes. Orange to blackish-brown opaque 

 masses, translucent in thin pieces ; fracture uneven, waxy, some- 

 what resinous, occasionally exhibiting microscopical crystals of 

 aloin ; odor distinct, unpleasant ; taste nauseous, bitter. The pow- 

 der is dark brown and gives an immediate deep reddish color 

 WITH COLD nitric ACID or with solutions of the alkalies. 



About 70 per cent, of Curacao Aloes is soluble in cold water. 

 It is almost completely soluble in 60 "per cent, alcohol or boiling 

 water ; on cooling the solution made with boiling water there sep- 

 arates from 40 to 60 per cent, of " resin of aloes," which is sim- 

 ilar to that of Socotrine aloes. About 66.6 per cent, is soluble in 

 chloroform and not less than 10 per cent, in ether. It contains 

 less than 8 per cent, of moisture and yields from 1.5 to 4 per cent, 

 of ash. 



