J 14 



DAIRY BACTERIOLOGY 



may inhibit the activity of the useful and the harmful organisms 

 alike. In order to clear up this question, the author made a 

 series of souring experiments, in which milk heated for half an 

 hour to various temperatures was used. The experiments were 

 all made with two grades of separated milk, one showing a low 

 bacterial count (A), and the other being an average retail milk (B). 

 The samples were inoculated with 1 per cent, of a culture of lactic 

 acid bacteria in milk. 



Spongy curdled, c = Cheesy (casein contracted and much 



f = Fluid, g = Gelatinous curdled, 

 clear whey), fg = Semi-solid. 



See further under the " Fermentation Test." 



The acidity is given in Soxhlet-Henkel degrees (see p. 161). 



The original acidity of the milk was 7 ; t 1 ]? acidity of the sterilised milk was, however, 8. 



