hj means of Soda. 37 



If we separate them from the liquor after its complete cool- 

 ing, if we wash them in the smallest quantity of water 

 possible, and dry them speedily by squeezing them between 

 several sheets o^' blotting paper, we shall have nothing but 

 pure crystals of barytes without mixture of acetate. I as- 

 certained this in the following manner : 



1st, T exposed a part of these crystals to the air : in a few 

 days, the distilled water with which I washed the carbonate 

 obtained, gave no more precipitate by the a-ddltion of the sul* 

 phuric acid, the carbonates, or alkaline sulphates. The whole 

 mass of crystals had therefore been converted intocarbonatCj 

 which would not have taken place if they had contained 

 acetate of barytes. 



2d, I dissolved two or three grammes of these same cry- 

 stals in distilled watery the solution blued turnsole paper 

 which was reddened by an acid ; there was an excess of al- 

 kali therefore. 



I added some drops of sulphuric acid to this solution, 

 and there was formed a solution of sulphate of barytes. I 

 tried the liquor again with the reagent paper, and I still 

 found an excess of alkali. I added by degrees siil phuric 

 acid, until there was a slight excess of acid in the liquor : 

 I filtered it, and found no more barytes, but a little free sul- 

 phuric acid ; this would not have happened if the crystals 

 had contained acetate of barytes : for upon this supposition^ 

 at the moment when the excess of acid beo;an to become 

 sensible to the reagent paper, there must have been only a 

 very small quantity of acetate of barytes decomposed, and 

 acetous acid set at liberty. The filtered liquor should there- 

 fore have contained a slight excess of acetous acid, and 

 more acetate of barytes not decomposed; which is contrary 

 to the result of experiments. 



3d, Tlje mother water of the crystals employed in the 

 preceding experiments, should contain nothing except the 

 little pure barytes which the cooled liquor could hold in 

 solution, besides the whole of the acetate of soda which had 

 been employed. What also demonstrates the analysis of 

 these mother waters, is, to pour alcohol into them as- 

 M. Porperes points out* The brilliatit lanunce which are 

 Xiomod^l C3 deposited 



