366 



Nexitralizcd 

 ■wi'h po'.ash 

 detonates. 



Kiirlc solution. 



Not a gum- 

 resin. 



but a simple 

 substance. 



occurring ni 

 «thtr j;»^ants. 



ANALYSIS OF ALOi:^. 



Alcohol at 38® dissolved only one thirtieth its weight of 

 the yeliow acid. The solution was a very deep red. 



Hot mineral acids dissolve this j-ellow matter without 

 CTolving any thing ; but it is soon after dcpositedj in con- 

 sequence of its insolubility. 



Potash forms with it a compound of a deep red, ancl 

 capable of crystallizing. This rod salt detonates with the 

 violence of gunpowder, cither when exposed to a certain 

 degree of heat, or touched with a burning coal; and after 

 burning leaves a slight coally trace, and a remarkable smell 

 of prussic acid, which leads to a suspicion of the presence 

 of nitrogen. 



This red detonating substance is easily produced hy pour- 

 ing on the yellow acid of aloes a weak hot solution of caustic 

 potash, which has but a slight solvent action on it. 



The nitric solution, from which the yellow aloetic acid 

 has been separated, was saturated by potash. At the end 

 of twenty-four hours a very small quantity of red detonating 

 jTiatter was deposited. JNitrate of lime being added to it, a 

 copious precipitate of oxalite of lime took place, which, 

 when well washed and dried, weighed 3*5 gram. [54 grs.J 

 The liquid separated from the oxalate of lime was pre- 

 cipitated by nitrate of lead ; and the precipi-tate, treated 

 with a third of its weight of dilute sulphuric acid, yielded 

 about a gramme [15*4 grs.] of malic acid partly dried. 



§ VII. From these facts it follows, that aloes is not a 

 gum-resin, as has been supposed, since neither of these two 

 principles is found combined in it. Consequently too it 

 cannot be confounded with the resins, though it is more 

 similar to them than to the gums. It is therefore a prin- 

 ciple sui generis, which from its properties I would call 

 resinoumer. This immediate principle is probably very 

 common, and has its species, like other vegetable matters. 

 It is this, that was at first confounded with resins, that has 

 been sometimes taken for oxigenated extract, and that Mr. 

 Vauquelin has made known in his interesting paper on the 

 different species of cinchona*. It is the same substance, 

 too, that is deposited in greater or less quantity from the 



See Journa!, vol. xix, p, 106, 2Q3. 



decoctions 



