114 COMBUSTIBLE ACIDS. 



lead was collected on a double filter, washed, 

 and dried in the temperature of about 150. It 

 weighed exactly 22*25 grains. Now, it con- 

 tained 14 grains of protoxide of lead ; hence, 

 it was composed of 



Protoxide of lead 14 

 Tartaric acid 8-25 



22-25 



This tartrate being neutral, and 14 being the 



weight of an atom of protoxide of lead, it is evi- 



Atom of dent that 8 '25 must be the weight of an atom of 



tartaric 



acid. tartaric acid. We see from this that anhydrous 

 tartrate of potash is composed of 



1 atom tartaric acid 8 '2 5 

 1 atom potash 6 



14-25 



For 14*25 grains of it, the quantity employed in 

 the experiment, contained just 8'25 grains of 

 acid. 



3. In the experiments described in the Annals 

 of Philosophy, (second series, II. 139.) 9*5 grains 

 of crystallized tartaric acid were saturated with 

 ammonia, and the solution, after being rendered 

 neutral, was mixed with a neutral solution of 

 6*25 grains of calcareous spar in muriatic acid ; 

 and the whole being evaporated to dryness, a 

 quantity of tartrate of lime was obtained which 





