BACTERIA AND BUTTER-MAKING 213 



A second advantage of pasteurizing cream is that it destroys 

 the disease germs. Butter would seem to offer an opportunity 

 for the distribution of the germs of contagious diseases. 1 The 

 ripening and churning do not destroy the pathogenic bacteria, 

 and we naturally expect to find them in butter. Market butter 

 frequently does contain the tubercle bacillus, as has been dem- 

 onstrated by many examinations of market butter in Europe, 

 and in America as well. The pasteurization of the cream is the 

 only means that can be adopted for thoroughly protecting but- 

 ter from this source of danger. It should be stated, however, 

 that although theoretically butter may be a means of distributing 

 any of the contagious diseases which are liable to be in milk, no 

 data are at hand which indicate that this actually occurs. While 

 we have many instances of epidemics due to milk, none have 

 yet been reported that are attributed to butter. Whether this 

 means that butter is not a source of danger, because the ripening 

 process has injured or destroyed the disease germs, or whether 

 it is simply lack of evidence, it is too early to state. It is signif- 

 icant, however, to remember that the development of lactic bac- 

 teria in large numbers has a tendency to destroy other bacteria 

 that may be present. Inasmuch as the ripening of cream re- 

 sults in the enormous development of lactic bacteria, it is pos- 

 sible that this process actually removes from the butter some 

 of the danger of its distributing ordinary diseases. The con- 

 clusion, however, does not apply to the tubercle bacillus. 



GENERAL VALUE OF STARTERS 



The almost universal adoption of starters in butter-making 

 is in itself enough to indicate that the butter-makers have found 

 them of value. Briefly summarized, the effect of the wide use 

 of starters has been to raise the general quality of the butter. 

 While perhaps the high grades of butter are not any better to- 

 day than they were before the days of starters, there is a much 



i Reitz. Cent. f. Bact., II., xvi., p. 719, 1906. 



