Il8 LILIACE^E 



heat is sometimes used for evaporation. When of proper consist- 

 ence, the evaporate is transferred to kegs, monkey skins, or boxes, 

 and shipped by way of Bombay and Zanzibar. 



Socotrine (Zanzibar) is a highly esteemed article, comes in yellow- 

 ish-brown masses, sometimes soft, odor aromatic, saffron-like, never 

 fetid or putrid and a nauseous and bitter taste, easily broken into 

 pieces with conchoidal fracture and sharp edges, readily splinters. 

 Does not possess any crystalline characteristics under the microscope. 



Curacoa, from the Dutch West Indies, is preferred by some to 

 Socotrine. This variety comes in orange to blackish-brown, opaque 

 masses, fracture surface, uneven, waxy, somewhat resinous; odor, 

 characteristic but not aromatic as in the socotrine variety. 



Cape Aloes, the South African Aloes, comes in reddish-brown or 

 olive-black masses, usually covered with a yellowish dust, in thin 

 fragments, transparent and of a reddish-brown color; fracture, smooth 

 and glassy; odor, quite characteristic. 



CONSTITUENTS. The active principle of these different aloes is a bitter 

 neutral principle having the general name of aloin, but slightly dif- 

 fering in each variety, forming possibly a homologous series; these 

 aloes may be distinguished by their characteristic reactions with dif- 

 ferent reagents. It should be stated that the various processes of 

 assay for aloes thus far proposed give discordant results. A small 

 percentage of emodin is found in various varieties. Cape aloes 

 contains 0.8 per cent, of this principle. Ash, not exceeding 4 per cent. 



70 a. ALOE BARBADENSIS. BARBADOES ALOES. Prepared from the leaves of 

 Aloe chinensis, Steud and A. Vera, L. by boiling the juice or by making a 

 decoction of the leaves; it is inferior to the other varieties. Its color varies, 

 but it is usually dark brown, approaching to black, opaque even at the edges, 

 and with a dull fracture; it is further distinguished by its nauseous odor. 

 A solution of i part in 100,000 of distilled water produces a fine rose color on 

 the addition of gold chloride or tincture of iodine, all the others, except Natal 

 aloes, producing only a slow change, a feeble color, or no color whatever. 



TESTS. SOCOTRINE. The powder (dark brown) when mounted under the 

 microscope in almond oil, shows yellowish- to reddish-brown, irregular 

 or angular fragments; upon addition of nitric acid yields a yello wish- 

 to reddish-brown solution. 



CURACOA. Powder (deep reddish brown) when treated as above shows 

 numerous blackish brown more or less opaque and angular frag- 

 ments; with nitric acid, yields a deep red liquid immediately. 



CAPE. Powder (greenish-yellow changing to light brown on aging). 

 When treated as above and mounted under microscope it shows 

 numerous distinctly angular bright yellow fragments. Nitric acid 

 produces a reddish-brown liquid changing to purplish brown and 

 finally greenish. 



GENERAL TEST. Intimately mix i Gm. of Aloes with 10 mils of hot water 

 and dilute i mil of this mixture with 100 mils of water; a green fluores- 



