and the formation of Gypsum and Magnesian Rocks. 171 
50°7 of hydrated chlorid of magnesium, and 10:0 grms, of hydrated 
sulphate of soda, the three chlorids being in the proportion of 
hours there had separated a crystalline precipitate, weighing 
‘288 grms., and consisting of carbonate of lime with only 2°6 p.c. 
between dolomite and 
ut 125° F. De 
ind that solutions of bicar- 
te of magnesia decompose chlorid of calcium in the cold, or 
at temperatures below 212° F. with precipitation of nearly pure 
carbonate of lin although th assertion of the latter, that sul- 
phate of lime decom by the same agent, 1s, as I sh 
