1918.] DAIRY FAjaMING DAIEYING. 879 



wash water used was 60 gal., the cans being rinsed after washing. In dairy B 

 tlie milli had a high germ content. From 60 to 80 cans were washed in the 

 same lot of wash water, the amount of water being about 25 gal., and the cans 

 were not rinsed after they were washed. The cans were washed immediately 

 after the milk was poured from them, and the plating of tlie rinse water was 

 made in from one-half to four hours. 



More than 1,000,000,000 bacteria were removed from each of 39 of the cuua 

 washed in dairy A, and from each of 3S others the numl)er was more than 

 100,000,000. Even larger numbers were removed from the 56 cans washed In 

 dairy B. In only 4 of the cans in this dairy was the number smaller than 

 100,000,000. Had these 170 freshly washed cans been fiUed with sterile milk 

 the resulting germ content would have varied from 197 to 2,557,000 per cubic 

 centimeter. The results of successive rinsings vpith sterile water indicate 

 that, while a considerable fraction of the germ life in the cans was temoved by 

 the first rinsing, it is by no means the entire germ life present. 



Fifty cans washed, steamed, and left 30 hours uncovered and inverted on a 

 rack, if filled with milk would have added to tlie milk an average of 8 bacteria 

 per cubic centimeter. Fifty cans similarly cleansed but left 30 hours witn 

 the lids on, if filled with milk would have -added to the milk an average of 

 1,816 bacteria per cubic centimeter. Fifty cans washed but not steamed and 

 held 30 hours uncovered and inverted on a rack, if filled with milk would have 

 added to the milk an average of 27,164 bacteria per cubic centimeter. Ten cans 

 similarly cleansed, but held 30 hours with the lids on, if filled with milk would 

 liave added to the milk an average of 128,730 bacteria per cubic centimeter. 

 Ninety-one milk cans that had been washed, rinsed, and steamed at tne 

 dairy and covered with their lids, examined as they were about to be used 

 on several dairy farms showed that had they been filled with milk they 

 would have added to the milk an average of 23,523 bacteria per cubic centi- 

 meter. The treatment of these cans at the farms was not uniform, either as 

 to their being kept covered or as to the length of time elapsing before their 

 use. 



A comparison of the germ content of each of 153 milk cans after the cans 

 had been emptied and washed, but not rinsed or steamed, and the germ con- 

 tent of the milk previously held by the cans, in most cases revealed no direct 

 relationship. However, taken as a whole, the dairy which received the milk 

 with the higher germ content also had the cans with the higher germ content. 



An examination of 134 freslily washed cans and of the water in which they 

 were washed showed that the wash water became heavily seeded with bacteria 

 during the washing process. However, the extremely large numbers of bac- 

 teria found in some of the washed cans could not be accounted for by con- 

 tamination from the wash water. 



Bacterial counts were made of a number of washed but unsteamed milk bottles. 

 The results show that if these bottles had been filled with milk the germ content 

 of the milk would have been increased by an average of 1,339 bacteria per cubic 

 centimeter by the freshly washed bottles and 12,930 bacteria per cubic centi- 

 meter by the bottles held 24 hours after washing. 



The experiments reported in part 2 were designed to test the influence of the 

 various unsteamed utensils upon the germ content in actual dairy operations, as 

 shown by the difference in the germ content of the milk handled in steamed and 

 in unsteamed utensils. The steaming consisted in holding the utensils in a 

 chamber filled witli flowing steam for about an hour, except that some of the 

 pails and cans were held over a steam jet for two to three minutes. Bacterial 

 examination of the utensils showed that this steaming was satisfactory. 



