OF MAGNESIA. 301 



Carbonic acid . 507512 



Magnesia . . 47-6334 



Deutoxide of manganese 0-2 117 

 Water . . . 



100* 



The salt is obviously anhydrous, and composed 

 of 



1 atom carbonic acid 2-75 or 53-411 



2-5 - 45-782 



5-25 



It would appear from comparing the constitu- 

 ents of the neutral salt with those of the native 

 anhydrous carbonate, that in the native rock a 

 little of the acid has been dissipated. My speci- 

 men was from the surface of the rock. No 

 doubt the same was the case with the specimen 

 analyzed by Stromeyer. It would be interesting 

 to know whether specimens from the interior 

 parts of the rock would be found to contain 

 their full complement of carbonic acid. 



It is obvious from Berzelius' analysis, that the 

 artificial carbonate of magnesia (obtained by ex- 

 posing a solution of magnesia in carbonic acid 

 to spontaneous crystallization) is a compound 

 of 



* Untersuchungen, p. 1^0. 



