188 



BACTERIA IN MILK AND MILK PRODUCTS 



When received, Specimen No. 1 contained 3000 bacteria per c.c., and 

 Specimen No. 2, 30,000 per c.c. 



There are two points in this table which may be noted. First, it 

 may be seen that at 32 F. (0 C.) there is a decline in the number of 

 organisms both in good and bad milk during the first 168 hours. At 

 all the other temperatures, to which there is no exception, there is a 

 rise in the number of organisms. Secondly, the numbers of bacteria 

 at 20 C. in forty-eight hours are equal to the numbers at 35 C. in 

 twenty-four hours, and in both instances the number is phenomenally 

 high. 



In 1900, Mr Swithinbank and the writer conducted a series of 

 experiments as part of an inquiry into the behaviour of bacteria in 

 milk, during which careful observation was made of a certain milk 

 from the time it was drawn from the udder up to thirty days, and then 

 subsequently after two years. Further, the observations were made 

 at three different temperatures. Broadly speaking, the conclusions 

 were as follow : 



First, there was an extremely rapid increase in the number of 

 organisms in the first four hours, particularly at 37 C. At the 



