142 
IOWA ACADEMY OF SCIENCE 
The cost of treatment varies greatly with the degree of hardness of the 
water. Pair boiler waters cost about one cent per 1.000 gallons. Prom this 
minimum the cost increases to ten cents, with the average about three cents 
per 1,000 gallons. 
All waters cannot be made good boiler waters by softening. Very hard 
waters are likely to contain already some sodium sulfate. To remove calcium 
sulfate by the method described means necessarily an increase of sodium 
sulfate. If the total quantity present exceeds about 600 parts per million, the 
result is foaming in the boiler. 
Iowa waters are hard and trouble with them in boilers and in other indus- 
trial uses is well-nigh universal. The trouble will not disappear of itself, but 
will become more acute as the industries of the state increase. I deem it 
worth while to call the attention of men of science to this most scientific 
remedy which has been proved wholly practicable on a large scale. It ought 
to be as practicable for a large stationary power plant or a manufacturing con- 
cern as for a railroad. In every town of considerable size there are numerous 
power plants, often laundries, tanneries and the like, and it would seem reason- 
able for them to unite in the erection of a softening plant for their common 
use if the method of solving their difficulties regarding water were made 
clear. 
