1 3 J)&rr&cq's Ohfcrvations 



hitely the fame weight as that produced by the diftillation of 

 the acetite of copper; that is to fay, it weighed 22 parts. 



From this refult. it is evident that the charcoal obtained by 

 diftilling acetite of copper does not ariie from the acetous 

 acid containing more than the acetic acid, ftfifGe the latter, 

 when fubjected to the fame operation, gives an equal quan- 

 tity. In my opinion, that produced in thefe operations docs 

 tiot arifc from a portion of the acid decompoied, the quan- 

 tities of which ought to vary according to the progreis of the 

 decempofition. Experience authorizes me to believe that 

 the difference which may exift between the two acids m 

 queftion does not depend either on the proportions of the 

 oxygen or of the charcoal. I fuperintended fome trials, not 

 on the condiment principles of vinegar, but on vinegar itfelf* 

 and the kind of mucilage with which it is accompanied. 

 Before I defcribe this labour I muft not forget to obferve that 

 C Chaptal furriifhed me with the idea % his obfervations 

 on the acetic and acetous acids* He fays on this fubjecl:, 

 that the acid of vinegar may be eonfidered as exifting primi- 

 tively in a ftate almoft faponaceous ; which diminifties it* 

 action, and weakens its properties. 



After having ascertained, by fome experiments, the exift- 

 ence of this extractive or mucilaginous principle, I endea- 

 voured to feparate it. Diftillation as well as filtration were 

 found to be imperfect means : my vinegar always contained 

 mucilage : it remained nearly the fame. However, by com- 

 bining it, after diftillation, with alkaline bafes, it depofited 

 very little of that flaky matter called extractive matter* 

 Hiving not forgot, during thefe fefcarehes, the opinion of 

 C. Adet, who fays that the quantity of water might occafion 

 the difference between the acetous and acetic acids, com- 

 paring the obfervations of thefe two chemifts, I made fome 

 fertperiments, which appear to roe to be interfiling; but I 

 fhall defcribe that only which appeared to me to be moft 

 conclufive. 



Entertaining the idea that there was no difference between 

 the acetous acid and the acetic, but a larger quantity of wa- 

 ter, and an extractive or mucilaginous matter, I endeavoured 

 to find the proper means of feparating the former from it, 

 and bringing it to the ftate of acetic acid. For this purpole, 

 I prepared muriate of lime, which I ftronglv calcined. After 

 reducing it to powder, I put it into a tubulated retort, and 

 poured over it common acetous acid with an apparatus proper 

 for receiving the products. The retort, which was on a fand- 

 bath, being expoJcd to a gentle heat, me matter immediately 



entereS 



