and the formation of Gypsum and Magnesian Rocks. 178 
nesia; and by adding known quantities of carbonate of soda to 
asolution of chlorid of magnesium and passing a current of 
lagers acid through the mixture, I have found it easy to ob- 
n permanent solutions, containing not less than 21:0 grms. of 
Sabhiien vichinnes of magnesia ina litre. Bineau, by prolonging for 
several days the action of carbonic acid, obtained a solution 
which contained in a litre 11-2 grms. of magnesia (equal to 23°5 
rs. of magnesian ee combined with very nearly two 
cE Meriben of carbonic 
observations of i. “Rhos and of Longchamp, show that 
the presence of alkaline chloride, sulphates or carbonates, as well 
magnesian salts, increases the solubility of carbonate of 
st grienin in water. This may explain the great difference 
tween the determination of Bischof, in which all foreign salts 
were excluded from the solution, and the experiments of Bineau 
and myself, with solutions which always a salts of soda 
or magnesia. That the presence of such salts does not, on the 
renee eso the solubility of shasta of lime, is appa- 
rent 
nesia, with sufficient muisiaie cid a form sorpcoirmcr ai dapat 
Such solutions, whet transferred to closed vessels, were sponta- 
decomposed, hydrated carbonate of magnesia separatin 
while a bicarbonate remained in solution—(Ann. de Chim. et 
vt , [8], li, 802.) 
sim decomposition of the gen os of mag- 
ocarbonate and bicarbonate i is ase ae 
Plautagenct ring was left to erepetate in an open basin in 
mmer, spin volume was to one-fifth, The 
ler solution was iain decanted from a os orig gore of sae 
_ t0.0°772 grms, of carbonate of magnesia to a litre of 
a trated er which contained 1 no a bat iulteadiace of bicar- 
bonate and ehlorid of r sium the separation of the 
