400 R. J. Southworth—Solutions of Hydrated Salts. 
e.c. In each of the steps, and in the final result, this experi- 
ment agreed with the theorem. This method was pursued 
where the first experiment with a salt showed a close agree- 
ment with the theorem. In those cases where there was a dis- 
agreement between the calculated volume and the observed 
volume of the solution, the weight of salt required to raise the 
volume of the solution one cubic centimeter was determined by 
direct experiment. For instance, barium chloride, with the 
formula (BaC],.2H,O) by calculation contained one cubic cen- 
timeter of H,O in 6°777 grams, but the quantity required to 
raise the volume of the solution one cubic centimeter was 3°89 
grams. If the specimen of barium chloride used contained 
4H,O, the experiment would give a result agreeing with the 
terms of the theorem. 
Salt used. By calculation. By experiment. 
Na,CO,.10H,O 1°588 1°59 
Na,SO,.10H,O 88 1°63 
Na,SO,.H,SO,.3H,0 4083 3°25 
Na,02B,0,.10H,O 2-122 2°12 
Na,HPO,.12H,O 1591 1°59 
BaCl,.2H,0 6-777 3:89 
SrCl,.6H,O 2-468 2°47 
MgSO, .7H,0 1-954 1°95 
Zn8O,.7H,O 2°277 228 
NiSO,.7H.O 2-298 2-28 
FeSO..7H.O 2-206 2-9 
CuSO. .5H,O 2-771 2°77 
Al,(SO,),.18H 2-058 2°06 
AIK(SO,),.12H,O 2°196 29 
INH,(SO,),.12H,O 2-099 2" 
CrK(S0,),- 12H, 2°31 2°31 
The first column of the table gives the formule of the salts 
according to the last American edition of Fownes’s Chemistry. 
The second column gives the weight in grams that contains 
one cubic centimeter of saline water, according to the formula. 
The third column gives the weight in grams found by experi- 
ment to increase the volume of the solution one cubic centime- 
ter. n examination of the table will show a close agreement 
between the results of calculation and experimentation, with 
the exception of barium chloride, which has been referred to, 
and the acid sodium sulphate. The disagreement between the 
calculation and observation in this instance may possibly be 
explained by the salt decomposing in the act of dissolving, 
separating into sodium sulphate, which is dissolved, and hydro- 
gen sulphate which unites with the water. This would agree 
with the strong acid reaction of the solution. 
