2. 
a 
The 
g the results before you. 
Solubility of Gypsum. 
SOLUBILITY OF GYPSUM 
I thought it would be of interest to supplement the above 
information by a few careful experiments on the solubility 
IN SOLUTIONS OF “SoDiIUM CHLORIDE. AT 
of gypsum in solutions of common salt of various strengths, 
“ According to Lassaigne, 1 part of gypsum dissolves in 
and I now have the pleasure of layin 
332 parts water at any temperature, but according to 
Poggiale the solubility is greatest at 35° C., 1 part of the 
solubility is increased by the presence of common salt, hence 
salt dissolving, at that temperature, in 593 parts of water, 
the occurrence of gypsum in salt springs.” 
at 0° C. in 488 parts, and at 100° C. in 460 parts. 
Grammes SO, Ca20H; 
NG CL 
SoLurion. 
Lt ag 
EGC a af | a) 
. Rese eeasesess 
AI Samsesseseeennneer 
aes HERES esesSene 
Baas HGEUEEBOREen eb eseiseseseaea 
eae Te nc i (Ye eam fi FOSS est cf noes sa 5 
HH AEE EE BSE EH = 
iff rd 40 ce PFT 2 SHER SSUESSEsenes|- 
Beaaoeea ELEEEEe a 
ca a © 3 Ps } BS 3} o 6 8 
The results are given in grammes of calcium sulphate 
Oie.et of 
a solution of common salt of the required strength was 
‘+5 C. Two grammes of artificially prepared 
Ca.20H2, was weighed 
(SO,Ca.20H;) taken up by digesting with solutions of 
sodium chloride in distilled water of strengths varying from 
The method of experiment was as follows :—15 
1 per cent. to 10 and 15 per cent. 
pure gypsum, of the composition SO, 
prepared at 15° 
