332 WATER HYGIENE 
5. An elimination of chlorine taste in the treated water which is so 
often found where hypochlorite is used. 
6. A decrease in the cost of the chemical required. 
7. The change in the rate of application is quickly and more easily 
accomplished. 
8. Absorption of the gas is more rapid. 
Fig. 61.—Automatic Control Chlorinator. (Wallace-Tiernan Co.) 
Dutton (1917) reported that with hypochlorite at 7 cents per 
pound and liquid chlorine at 20 cents, it would cost $1.07 to treat a 
million gallons of water with bleach and 28 cents to use liquid chlorine. 
With such data at hand, it is evident that the liquid chlorine is the 
more efficient chemical to use. 
The advantages of softening a water supply with lime are becoming 
more and more apparent. Houston has shown that lime is a bac- 
tericidal agent and he proposed the addition of this chemical for ster- 
