166 



THE IRRTGA'lION AGE. 



we have observed that by the use of the 

 ordinary tin drum milk cooler filled with 

 well water, which with us has a temperature 

 of from 70 to73 degrees, milk, may be re- 

 duced in temperature ten degrees; that by 

 running it over the cooler a second time 

 the temperature may be brought down five 

 degrees more; and that by wrapping the 

 cans in which the milk stands in wet bur- 

 lap or gunny sacks the temperature may 

 be still further reduced to that of the at- 

 mosphere or lower. During the first 

 fifteen days in July, including the hottest 

 days and nights of the season and the hot- 

 test twenty-four hour period recorded since 

 the establishment of the weather bereau 

 in Phoenix, the average temperature of 

 the night's milk in the morning, under 

 this treatment, was 71 degrees, which was 

 less than the average minimum tempera- 

 ture of the atmosphere for that period. On 

 very warm nights the temperature of the 



milk went several degrees below that of 

 the surrounding air. Under this treat- 

 ment the iacrease of acid in the milk 

 during the night was very slight. The 

 average per cent of acid in the milk im- 

 mediately after milking, during the first 

 ten days in July, was 165 per cent, while 

 the same milk on the following morning 

 showed a presence of only 17 per cent of 

 acid. Milk seldom smells or tastes sour 

 when containing less than 3 per cent of 

 acid. 



"With these facts to base conclusions 

 upon we feel safe in stating that, with the 

 exercise of reasonable cleanliness in milk- 

 ing and in the care of utensils, and by 

 taking proper care in cooling, milk may be 

 delivered at the factory in good condition, 

 and that there is no excuse based on reason 

 for what we deem the criminal adulteration 

 of milk by the use of chemical 

 preservatives." 



