ON ACETIC ACID AKJD ACETATE?. 341 



I introduced a hundred parts, by measure, of the liquid 

 to be assayed into a tube, which was' 5 dec. [19-6 inch.] 

 long, and 5 or 6 mil. [0*2 of an inch] in diameter, and 

 closed each end by a small cork. I put in carbonate of 

 potash sufficient to render the separation complete, and iu 

 order to bring the spirituous liquor to the part of the tube, 

 where I had measured the whole of the liquid before I put % 

 in the carbonate of potash, I let out a portion of the 

 liquid below, by drawing out the cork from the bottom, 

 so as to compensate the increase of bulk occasioned by the 

 addition of carbonate of potash. Thus I avoided the 

 errours, that any inequality in the bore of the tube would 

 have occasioned. 



The pyroacetic spirit thus separated is not at its greatest 

 degree of dryness : but it is in a sensibly uniform state, and 

 may be subsequently rectified hy other processes.' 



In a similar way I proceeded with all the liquid mentioned 

 in this paper. 



As to the aeriform products, the separation of the car- Aeriform pN*. 

 bonic acid was effected in the solution of barytes contained ducts * 

 in the first phial. I ascertained its quantity by examining 

 the carbonate of barytes formed during the process. The 

 hidrogen gas I collected in the pneumatic apparatus. 



I will not assert, that there is exactly the same precision Calculations. 

 with regard to all the acetates ; but the variations appeared 

 to me too small, to be noticed in researches of this kind. 

 If an acetate of the same metal be distilled several times, 

 we shall find slight variations from one experiment to an- 

 other, which require numerous repetitions, that we may 

 take the mean of as many operations as possible. We 

 should also take every care, to preserve the same degree of 

 temperature throughout every operation, as well as in all 

 that are undertaken with a view of comparing the different 

 acetates with each other. 



These variations take place most generally in the acetates 

 that yield the greatest quantity of pyroacetic spirit; and it 

 was by taking the mean terras of several operations, and 

 particularly attending to the greatest and smallest quantities 

 of each gubstancc produced in distilling all these salts, that 

 I determined the proportions and order in the following ge- 

 neral table. 



