176 On some Reactions of the Salis of Lime and Magnesia, 
par 
prepared gypsum, with distilled water, at 60° F. The lime was 
thrown down as oxala ate, and indicated one part of sulphate of 
lime to 483 parts of water. Another portion of the same aye 
tion was evaporated at a gentle heat until crystals of gypsu 
separated, and the clear saturated ease decanted from ae 
erystals after twelve hours of re pos 60° F., contained one 
part of sulphate of lime for 372 ee of a which approaches 
closely to the determination of 
In a late paper, by ae on the earthy carbonates 
already cited (Ann. de Chim. et de Phys., [3] li., nae), the author 
refers to a memoir of Mr. E. Marcha nd, who ts that a day 
of water may hold dissolved as bicarbonate, Ton 42 Dp 
carbonate of lime, and that sulphate of lime and alkaline biearbon- 
ay co- -exist in natural waters. These statements are con 
“Se though as will now be shown um may be ary 
talli 
Tess soluble salt than e um, or the carbonate of magnesia, 
would be deposited. I have Guint: eth ak from such 4 
solution under these conditions, tes, while bicar- 
bonate of magnesia remains in so. ee aa ae sulphate of a 
nesia speed | in the following experiments was care: 
and contained no traces of lime or free acid; its Aes 
gon did not alter the color of curcuma, but slowly restored that 
of e carbonic acid employed was evolved 
from limestone a iccchioie acid, and carefully washed, so that 
its solution was not troubled by nitrate of silver. 
‘To 500 c.¢, of water were einen twelve grams of sulphate of 
magnesia and half a gram of precipitated carbonate of lime, and 
