92 
TRANSACTIONS OF THE TEXAS ACADEMY OF SCIENCE. 
Water 
Silica 
Alumina and Iron Oxides 
Magnesium Oxide 
Calcium Oxide 
Sulphur Trioxide 
40.07 
40.00 
21.075 
21.43 
2.20 
2.21 
12.381 
12.38 
trace 
24.014 
24.01 
99.74 
100.03 
Calculated to contain 76.13 per cent MgS0 4 , 7H 2 0. 
A series of experiments demonstrated that the crude material yields 
crystallized MgS0 4 within one or two per cent of the analytical results. 
