224 Analysis of Aloes, 



This precipitate when collected -and distilled in a retort 

 yielded an ammoniacal liquor, from which it should seem 

 that the substance in question is nothing more than a coa- 

 gulated vegetable albumen. 



Action of Alcohol, — Four ounces of hepatic aloes were dis- 

 solved in alcohol : there remained an insoluble mass, weigh- 

 ing 4-3- drachms, which was albumen. 



The alcoholic solution was evaporated to dryness, and the 

 residue was boiled with water. It was entirely dissolved ; 

 but upon cooling the resin separated from it. By this 

 means we obtained three ounces of saponaceous principle, 

 and 2\ drachms of resin. 



From all the above experiments the author has drawn the 

 following consequences : 



1. Socotrine aloes are completely dissolved in boiling wa- 

 ter. The resinous part is separated from it by cooling. 



2. It is also dissolved in alcohol without leaving any re- 

 sidue. 



3. The parts which are soluble in water contain more 

 bitter principle than those which are soluble in alcohol, al- 

 though these last are not entirely free from it. 



4. The hepatic aloes differ from the socotrine, in so far 

 as they contain an albuminous vegetable matter, and less 

 resin than the latter. 



5. It is not completely dissolved in boiling water, for the 

 coagulated albumen resists it. 



6. It is not wholly dissolved in alcohol. This is the way 

 in which we may distinguish it very evidently from socotrine 

 aloes, even when their physical characters are the same. 



\ ' ! ~ 



XLII. Analysis of Aloes, By M. Bracoknot*. 



§ T. Aloes are procured from several plants which bear 

 the same name : at Morviedris in Spain the aloe vulgaris 

 furnishes three sorts, which only differ from each other in 

 the way in which they arc prepared. In the West Indies 

 the substance in question is extracted from the aloe barba- 

 densis, which, as well as the foregoing species, is regarded by 

 some writers as a variety of the aloe peifuliatd, and which 

 is cultivated in the most wretched soils. The aloe spi cat a c 

 a distinct species from the above, also furnishes juice of a 

 good quality; but the purest and most valuable is brought 

 in bladders from the island of Socotra, situated at the en- 

 trance of the Arabian Gulph in the Indian Seas: it is ob- 



* A finales de Chimie, tome Ixviii. p. SO* 



t tained 



