£2g ON ACETIC ACID AND ACETATES, 



6meil of the last portions too is more pungent than thai of the 



first. All these appearances depend on a spirituous very light, 



highly inflammable, and extremely pnuoent fluid, which 



^fonos at the clo>e of the distillation of acetate of copper. 



Their pyoa- Messrs. Derosne have given it the name of pyroacetic ether; 



cetic r?her . . ,, ' ... 



jnor« puberty ^ ut tn,s * eeuls to ine to ^e ae«ermiiiing its nature too pre* 



•pint. cisely, and 1 have cuded it by the more genera 1 term of py- 



roacetic spirit. 



ISo experiment I made indicated the presence * f mucilage 

 in the liquid jprodt.ct of ihe distillation, of ^erdigrise. It 

 appears to be composed at least of water, hceiic acid, and 

 py{pa< e c spirit. 



l>5ff*renceb(?« From ihese results ue may appreciate the * light but real 



twetn ;■ etc differences, that exist between vinegar and the product of 



acid and Tine* r> r 



gar, the distillation of acetate of copper; and which had for* 



n.triy led Derthollet apa Chaptal to believe the existence of 

 two acids. 



In English vinegar, for instance, there is a little acetic 

 acid, a little vegetable matter, and extremely little bpiritu- 

 ous liquor. In the product of distilled acetate of copper 

 there is more acid it is true, but no vegetable matter, and 

 much more spirituous liquor. On account of the lightness 

 of this liquor therefore, there ought to be more acetic acid 

 in the product of the acetate of copper, than in vinegar of 

 equal specific gravity. Accordingly Mr. Berthollet, having 

 saturated equal quantities of these two fluids reduced to the 

 same specific grayity, obtained more acetate from the former 

 than from the latter: and Mr. Chaptal has observed, that 

 vinegar required one sixth less of base than the product dis- 

 tilled from acetate of copper, under similar circumstances. 

 I have composed liquids in which a quantity of acid was 

 compensated by a portion of pyroacetic spirit, in order to 

 keep the specific gravity the same as that of vinegar; and 

 the quantity of base required to saturate each was exactly in 

 the ratio of the spirituous liquor. 



The vegetable matter too accounts for vineo-ar being 

 Vegetable ° . . 



matter, more highly coloured by the addition of sulphuric acid, than 



the product of acetate of copper. It accounts for the great-* 



er quantity of carbon in the destructive distillation of the 



gcetate formed by the combination of vinegar with potash, 



than 



