108 FLUORIC ACID AND ITS COMPOUNDS. 



Fluoric acid 27'859 or 1-3514 



Lime 72-141 - 3-5 



100-000 



The second column of figures exhibits the ato- 

 mic weight of fluoric acid, according to these 

 experiments. The reader will perceive that 

 the analysis cannot be perfectly accurate, be- 

 cause a different atomic weight is obtained from 

 every salt examined. 



From fluate of silver it is . . . 1-45965 



From Berzelius' analysis of fluor spar it is 1-39446 



From fluate of barytes it is . . . 1-35693 



From Davy's analysis of fluor spar it is 1-3514 



The highest atomic weight is 1-45965 and the 

 lowest 1-3514. 



* ^ P r epared some very pure fluate of soda 

 the author, by the following process i Two ounces of car- 

 bonate of ammonia were dissolved in water, and 

 a current of fluosilicic acid gas was passed 

 through the liquid till the ammonia was satura- 

 ted. The solution was then filtered into a silver 

 bason, and carbonate of soda added by small 

 quantities at a time, till the ammonia was al- 

 most all driven off, and fluate of soda formed. 

 The whole was then evaporated to dryness in a 

 silver bason, and the dry salt redissolved in wa- 

 ter and filtered again, to get rid of a little silica 

 which it still contained. The clear liquid was 



