346 , ON ACETIC ACID. 



can this principle be derived ? Is it from tlift basft^' But (his 

 cannot be, since ammonia was equally obtained from ace- 

 tate of lead. In this case it could be furnished only by the 

 acetic acid; or it must be allowed, that azote is only a mo- 

 dification of hidrogen. 

 D(ws nitrofjen He then inquires whether azote occur as frequently among 

 tMe aHlds^^^^' ^'^-^^^^^^^ acids, as among 'Minimal acids: because, if it be 



so, their classification should be altered. 

 Very pure sub- In repeating the experiments of Mr. Proust, it appeared 

 ployed. " essential to Mr. Trommsdorff, to eiri])loy only very pure 

 substances. Accordingly, in order to have acetic acid in 

 the purest state possible, he decomposed the acetate of pot- 

 ash by sulphuric acid; heathen saturated this acid with car- 

 bonate of soda well purified, and efaporated the saline so- 

 lution in a silver basin. The salt obtained, which he put 

 into a bottle with a ground stopper, was extremely white. 



In preparing the acetates Of potash and of lead he em- 

 ployed similar precautions. 

 Tliese distilled. lie took eight ounces of each of these salts, and intro- 

 duced them separately into three strong glass retorts. These 

 retorts were placed on the open fire of a furnace, and to 

 each was adapted a receiver, from which issued a glass tube, 

 terminating under a jar for receiving the gasses that should 

 come over. 

 The products. ' The products were, as every body knows, an acidulous 

 «thereous fluid mixed wilh oil. The alkali and carbone re- 

 mained in the retort; and in the decomposition of the ace- 

 tate of lead nothing of this salt remained but the lead ox- 

 ided. 

 The alkalis pro- Thus by the predisposing affinity of the alkalis for car- 

 noted thede- Jjqj^j^ acid, these determined the decomposition of the acetic 

 composition of ' ^ ^ , 



the acid, acid, to give rise to the formation of carbonic acid. The 



oxide of lead on the contrary, not having so great an affi- 

 nity for carbonic acid, gave out the acetic acid in its greatest 

 purity. 

 How does the '^'^^ autlior asks, whether the metallic base yielded up 

 metal act? oxigcn to burn the carbone ; or whether the attraction be- 

 tween an oxide and an acid be less powerful than between 

 an acid and an alkali. To answer this question, he would 

 wish a great number of experiments to be made. 



Th^ 



