[ ^97 J 



tartarin contained 45 per cent, real vitriolic acid, I diffolved 

 100 grains of it in fix ounces of water, and precipitated the acid 

 by muriated barytes, the refulting barofelenite weighed after 

 ignition 135,25, which proves as we fhall fliall prefently fee that 

 the vitriolated tartarin contained 45,078 grains of real acid. 



SeBion i^d. 



Of Soda and Vitriolated Soda, or Glauber. 



As foda may be had either chryftallized, efflorefced or defic- 

 cated, it will be neceflTary to examine the proportion of real al- 

 kali in each, in order to find the proportion in neutralized com- 

 pounds. 



ift. Im its cryftaliized ftate even when recently formed, I 

 found the proportion of its ingredients fomewhat variable, b ut 

 in the greater number of experiments the cryftals being dried in 

 filtering paper in a temperature not above 66^, and the air not 

 much difpofed to give out moifture. I found 100 parts of the 

 cryftals to contain 64 of water, 21,58 of real foda, and 14,42 of 

 fixed air. 36 Grains therefore of aerated but deficcated foda are 

 equal to 100 grains of the cryftaliized, that is, contain the fame 

 quantity of alkali. 



adly 



