170 FLUORIC ACID AND ITS COMPOUNDS. 



it in a very moderate heat for twenty-four hours. 

 A little of the water was then drawn off, and 

 tested with oxalate of ammonia and muriate of 

 lime. It did not become in the least muddy or 

 even opalescent, showing that it contained no 

 sensible quantity either of lime or fluoric acid. 



The fluate of lime, formed in this experiment, 

 was carefully collected on a double filter, washed 

 and dried, first in the open air, and then heated 

 to redness. Its weight certainly did not differ 

 by Tooth of a grain from 4*75 grains. 



From this experiment, which was repeated 

 four or five times before I succeeded in remov- 

 ing all ambiguity from the phenomena, it is evi- 

 dent that 5'25 grains of anhydrous fluate of soda 

 contain just the quantity of acid necessary to 

 saturate 3v5 grains of lime ; and that the fluate 

 si- thus formed weighs 4*75 grains. Hence, it must 



tion of flu. . 



ate of lime. COttSlSt Ol 



Fluoric acid 1'25 



Lime 3-5 



3*5 being the atomic weight of lime, and the salt 

 Atom of being neutral, it is obvious that l'%5 must de- 



fluoric acid. 



note the weight or an atom or fluoric acid. It is 

 obvious, likewise, that the anhydrous fluate of 

 soda was composed of 



Fluoric acid 1-25 



Soda 4 



5-25 



