264 SALTS 



obviously equivalent to 2 atoms. Tiius we see 

 that the crystals of this salt are composed of 



1 atom tartaric acid 8-25 



1 atom potash . 6 



2 atoms water . 2-25 



16-5 



The crystals used in the preceding experiment 

 were large and transparent, and had been pre- 

 pared with great care. I have had in my posses- 

 sion crystals of this salt in needles, which seemed 

 to contain no water of crystallization ; for, 14*25 

 grains of them, being dissolved in water, and 

 mixed with a solution of 20'7<5 grains of nitrate 

 of lead ; the liquid, being examined after the de- 

 position of the tartrate of lead, was found to 

 contain no sensible quantity of tartaric acid, or 

 of oxide of lead, by the tests of tartrate of potash 

 and nitrate of lead. 



18. Bitartrate of potash. This salt is seldom 

 or never quite free from tartrate of lime. 24 '75 

 grains of it were exposed to a red heat in a pla- 

 tinum crucible ; and the residue, being dissolved 

 in water, and mixed with 9 grains of crystallized 

 oxalic acid, was found to be quite neutral. 

 Hence, it is obvious that the constituents of this 

 salt are 



2 atoms tartaric acid 1 6-5 



1 atom potash . 6 



2 atoms water . 2-25 



24-75 



16 



