DAIRY INSPECTION 191 
effect it also usually exposes the apparatus to contami- 
nation with germ-laden dust. 
When facilities for sterilization by steam are not 
available, the milk vessels and utensils may be sterilized 
by submerging them for 20 minutes in a 0.1 per cent. 
solution of hypochlorous acid after they have been 
cleansed in the usual way. Hypochlorous acid is even 
more effective as a germicide than the hypochlorites, al- 
though the latter are 150 to 200 times as powerful as 
carbolic acid. A 0.1 per cent. solution will kill typhoid 
bacilli in 2%4 minutes. The solution may be conveni- 
ently prepared as follows: Mix together equal parts by 
weight of finely ground commercial bleaching powder 
(chloride of lime) and powdered boric acid; keep in a 
well-stoppered bottle and protect from light. Dissolve 
6 drams of the powder in a quart of water by shaking 
thoroughly, let stand for 24 hours and pour off the 
clear fluid; then add 4 quarts of water. This makes a 
solution containing 0.1 per cent. of hypochlorous acid. 
When milk bottles are submerged in this solution for 
20 minutes, drained for 10 to 20 minutes, and then filled 
with milk and capped, no odor or taste of chlorine can 
be detected in the milk. Milk can be strained through 
cheese cloth moistened with the solution without any 
effect upon the odor or taste. Tin vessels are not cor- 
roded. The powder from which the solution is pre- 
pared may be kept for some time under proper condi- 
tions, but the solution rapidly loses strength and be- 
comes ineffective in three weeks. Calcium hypochlo- 
rite has been in use for a long time as a disinfectant for 
water supplies and a solution containing 1 ounce to 125 
gallons of water is recommended for the sterilization of 
milk vessels and utensils, but it is much more expensive 
