290 J. K. MURRAY. 
Transport over rough roads by service car caused some 
petri dish cultures to be damaged and the records given in 
the following tables are not complete. 
Moruya Co-operative Cheese Factory. 
Count of total micro-organisms present in the raw and 
pasteurised mixed milks. 




Raw Milk. Pasteurised Milk. 
610,000 ‘| 875 
1,280,000 | 4,080 
654,000 512 
612,000 500 
206,000 220 
672,400 Average 2,650 

To obtain a better comparison with “‘ raw’’ vat conditions, 
the samples of pasteurised milk were taken from the bulk 
after its passage over the cooler; the actual efficiency of 
the pasteuriser would then be somewhat higher than the 
percentage (99°6) calculated from the figures. Cooling 
to renneting temperature is an essential part of the 
process, and contamination during cooling is legitimately 
recorded against the pasteurisation process. The investi- 
gations of Haglund® may indicate that cooling to a much 
lower temperature than that of renneting improves the 
product. Sammis and Bruhn! in their classical bulletin on 
the subject obtained an efficiency of over 997% using 165° F. 
with 1912 flash pasteurisers. MaclInnes and Randell” using 
the flash method at 180° F. obtained an efficiency at the 
outlet of the machine of 99°987% for cream. 
The work of Ayers and Johnston® indicates that some of 
the lactic streptococci may survive flash pasteurisation at 
165° F., while Weigmann, Wolff, Treusch and Steffen’ state 
that the results of their investigation go to show that 

