ont Ree eee Mae yp gl 
MS ESE ge ea ete ft ag 
— 
ERS oa Se le eee al eae ieee a 
* 
T.S. Hunt on Lime and Magnesia Salts. 53 
two Hecreseno of pure ere ep carbonate of lime was 
or so 
decomposition of the sulphate of magnesia was complete, and 
the carbonate of lime removed from the mixture held only 0°7 
er cent of carbonate of magnesia, while the residue contained, 
esides sulphate of lime, oe of magnesia with only 13 
er cent of carbonate o 
Marignac bad iowa ‘to form the double carbonate by 
heating in a similar manner solutions of magnesian chlorid with 
an excess of carbonate of lime. In this case, as I have shown, 
the decomposition, even after several hours at temperatures of 
150°-290° C. is but very partial, while the product analyzed by 
dilute acetic acid was chiefly carbonate of lime, mechanically 
mingled with magnesite and a small but variable proportion of 
the double carbonate ($ 34-36). In both cases the carbonate of 
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n subsequent experiments, pre it was shown that when 
a. 
are given, with many details, in § 39-42, and furt ner experi- 
Hydrated double carbonates of lime and magnesia, 
81. The results noticed in the last section gave rise to further 
inquiries into the affinity between the carbonates of lime and 
magnesia, and to the discovery of some artificial hydrated com- 
pounds of the two. The numerous hydrated double carbonates 
studied by Deville were all compounds of the alkalies (potash 
or — with magnesia or a magnesian oxyd. In his beautiful 
memoir on these salts published in 1851 (An. Ch. et Phys, [3], 
Xxxiii, 75-106), besides a series of double salts containing alka- 
ine bicarbonatés with nine equivalents of water, Deville has 
escribed numerous neutral double carbonates having the gen- 
eral formula C,MMO,, which are either anhydrous or combined 
with three, four, or ten atoms of water, HO; (H=1,C=6, O=8), 
n these ese salts, which are all crystalline, the cae metal i is either 
tassium or sodium, and the agnesium, nickel, 
cobalt or wet ek With zinc the goto of 1 the ht uble carbon- 
ate is less simple than for the preceding, being, according to 
Deville, 3NaCO, ,8ZnCO,,8HO. The mode in which these salts 
