174 On some Reactions of the Salts of Lime and Magnesia, 
I. 
On the reaction et solutions of bicarbonate ed lime and the 
sulphates of soda and magnesia 
10. If to a solution of bicarbonate of lime we add a portion 
of sulphate of soda or sulphate of magnesia, there are form 
by double decomposition, bicarbonate of soda or bicarbonate of 
magnesia and sulphate of =m which latter salt may be precipi- 
tated by the addition of alco 
and washed with dilute alcohol. It was completely soluble in 
water, but was again throw n down by alcohol, with the addition 
weighing, when ignited, 0-428 grms., which corresponds to 0°9 
grms. of carbonate of lime to the litre 
ML 400 c. Cc. of the same solution of bicarbonate of lime were 
12. 5002 c.c, of a recent solution of eee: of lime with 
20 grms. of hydrated sulphate of soda and an equal volume of 
alcohol, gave a precipitate of gypsum, which when dissolved in 
water and reprecipitated as in $10, gave 0°570 of sulphate of 
lime, equal to ‘838 grm. of carbonate of lime toa litre. The alka 
line filtrate was evaporated to dryness, the residue redissol st 
and precipitated at a boiling heat by a dilute solution of chlorid 
of calcium. The carbonate of lime thus obtained was free from 
sulphate, and concen to -445 grm. of carbonate of soda; 
pera pan mands 442. 
13. In consequence of this formation of gypsum, the solubili 
of carbonate of lime in carbonic acid ease is, as I have found 
very much increased by the presence of sulphate of soda, or 
phate of magnesia. To a little more than 200c. ¢. of lime-water 
“— added 4-0 grms. of sulphate of soda, and a stream of carefully 
ashed carbonic acid gas was then passed through the liquid for 
ag hours, at the end of which time the solution of the earbon- 
lime was nearly complete. On the addition of an equal 
a Se 
