MILK SURVEY OF THE CITY OF ROCHESTER 185 



determine the sanitary character of the milk, arrangements were made for 

 carrying out some special bacterial tests. The University of Rochester, 

 through its Department of Vital Economics, kindly offered the facilities 

 of one of its bacteriological laboratories to the bacteriologists employed 

 by the Survey. These laboratories were offered without expense to the 

 Survey and every convenience that could be desired was provided. The 

 Survey employed two bacteriologists at different times to collect samples 

 of milk and make bacterial tests. 



The total number of samples tested was 350. A number of milk 

 factories were visited and samples taken of the process of pasteurization 

 in order to determine the efficiency of this process. In such factories 

 samples were taken from the mixing tank in which the milk from the 

 cans was poured and mixed before pasteurization. If passed through 

 a clarifier before pasteurizing, samples were taken from the clarifier and 

 from each pasteurizer. They were then taken from the heater after the 

 milk was heated and from the holder after the milk was held at the re- 

 quired temperature for the required period of time. Another set of 

 samples were then taken from the cooler after cooling and from the 

 bottle filler after the milk had passed through the filler, but before it 

 entered the bottle. The last set of samples were taken from the filled 

 bottles themselves. Another series of samples were taken from the rail- 

 road platforms from the farmers' cans as they were received. 



The results of all this work are tabulated and summarized in Table 

 No. 89. 



TABLE No. 89 

 SUMMARY OF TABULATION OF BACTERIOLOGICAL TESTS. 



2. (CANS.) RAW MILK AS RECEIVED: 



Bacteria per cc. No. of Samples 



Below 50,000 18 



50,000 to 100,000 



100,000 to 200,000 60 



200,000 to 500,000 47 



500,000 to 1,000,000 



1,000,000 to 5,000,000 



3. SAMPLES FROM MIXING TANK: 



Bacteria per cc. No. of Samples 



100,000 to 200,000 



200,000 to 500,000 



500,000 to 1,000,000 



1,000,000 to 5,000,000 



4. SAMPLES FROM CLARIFIERS : 



Bacteria per cc. No. of Samples 



185,000 < 



190,000 



