£36 QN ACETIC ACID AND ACETATES. 



\vhich I always chose very long. Tu consequence nothing 

 escaped but permanently elastic fluids. 



In these liquid products three things were to be ascer- 

 tained: their specific gravity, thdr degree of acidity, and 

 their proportion of spirituous liquor. 

 Method of To rind the specific gravity, I first took the weight of a 



finding speci- sma |) pma j w ^ a g roum i s topple, which at the tempera- 

 ture of 15° [59° F.] contained exactly 10 gram. [154'4 grs] 

 ©f distilled water. The. weight of any other fluid contained 

 in this phial at the same temperature gave the specific gra- 

 vity directly. This method, on which Mr. Descroizilles 

 has published a very minute paper, is far from new; but 

 he has not ascribed to it all the advantages it actually pos- 

 sesses. It merits the preference particularly because it 

 avoids all friction from immersion in the liquor to be as- 

 sayed, and has no limits but the sensibility of the balance 

 employed. That I used was sensible to a thousandth of 

 a gramme, which gave me the specific gravity sought to a 

 ten thousandth nearly. 

 Objections an- To this method it has been objected, that the stopple 

 swered. roav \y e thrust in more or less in different experiments, so 



as to force out more or less of the fluid. The d lata- 

 bility and elasticity of glass too have been mentioned. 

 But let any person repeat the experiment several times on 

 the same fluid, andhe will find, that the differences will only 

 affect the thousandth or ten thousandth parts. This bot- 

 tle of a known weight is equally adapted for taking the 

 specific gravity of solid bodies. 

 Methods of To And the proportion of acidity of these liquids, I had 



finding their hoped, that by employing a substance, which by its own 

 iu |. re * action on a solvent should be divided into a soluble and 



insoluble matter, I should be able to substitute a law of 

 nature for the uncertainty of manipulations. Accordingly 

 I tried carbonate of lime. But acetic acid does not attack 

 this with sufficient vehemence, to attain the limit of its 

 action in a uniform manner: and having put some carbo- 

 nate of lime into a glass retort, in order to dissolve it in 

 acetic acid, I collected the fluid that passed over by dis- 

 tillation, and found it required repeated cohobation, before 



it 



