170 EXPERIMENT STATION RECORD. 



coDtaiES many kinds of germs in large numbers, at least, during work- 

 ing hours." 



Another experiment showed the variability of the bacteria content 

 of river, hydrant, and well water. An account is given of an outbreak 

 of typhoid fever the source of infection of which "seems inevitably to 

 have been by way of the milk, traceable to a slough and small creek 

 running through the pasture and stable lot of the farm." 



An exj)eriment was made on the eiJectiveness of direct steam for 

 sterilizing milk utensils, the results of which "go to show that 20 

 minutes' direct steaming will destroy most germs not in spore form." 



The results of other experiments are given on the germ content 

 of different kinds of milk and of i>asteurized products, the kind and 

 number of germs which may fall into the milk pail during milking, the 

 germs in the milk from the first part of the milking, and on cheese- 

 curd inflation or pin-hole formation. An account of some of the work 

 on cheese-curd inflation has already been given (E. S. E., 7, p. 991). 



"The inference to be drawn from these teste is that the germs which originated 

 the gas holes in the curds came from dirt falling from the flanks and udders of the 

 animals. 



"Many similar tests, and over 200 qualitative cultural tests upon milk drawn 

 through sterile milk tubes from 13 different cows, during both winter and summer 

 months, at Fargo, substantiate this conclusion. In all these tests of milk from the 

 normal udder no gas-engendering species have been taken. They have, however, 

 often been met Avitli in the milk open to dirt contaminations. Hence one may readily 

 see the economic importance of cleanly methods of work with milk when considered 

 from the standpoint of cheese making." 



PoTver tests of centrifugal cream separators, A. W. Richter 



( Wiscoiishi iSta. Bui. 46, pp. 38, figs. 5, dgms. 12). — " During the past 

 2 years a series of tests have been made to determine the power 

 required for running the diflerent kinds of centrifugal cream separators 

 in use at the Wisconsin dairy school. In these trials machines have 

 been managed and tests of skim milks made by representatives of the 

 dairy school, instructions of the manufacturers regarding the running 

 of the diflerent machines being strictly adhered to." 



Ten belt machines and 3 turbines were tested. Determinations were 

 made in each case of the capacity of the separator as operated, time 

 and power required for starting, and the steam and iwwer required for 

 running. The results are reported in detail and discussed. 



Some of the results are given in the following table: 



