TUBERCULOSIS. IO9 



It will simplify our study of the relation of milk bacteria 

 to health if we divide the diseases attributable to this source 

 into two classes. 



1. Definite Diseases Due to Specific Organisms. These 

 consist of a few clearly marked diseases, supposed to be pro- 

 duced by distinct microorganisms .which are capable of living 

 in milk. In some cases the bacterium is well known to bac- 

 teriologists ; in others it is not yet known. The important 

 diseases under this head are tuberculosis, typhoid fever, 

 scarlet fever, diphtheria, and one or two other rare diseases 

 to be mentioned later. 



2 . Indefinite Diseases. These are generally characterized 

 by intestinal disturbances, a diarrhea being an almost uni- 

 versal symptom. These diseases are more obscure in their 

 nature and quite obscure in their origin. Their cause has 

 never been traced to any distinct bacterium, and they are 

 probably not caused by any one kind of microorganism. 

 Cholera infantum and various forms of summer diarrhea 

 belong to this class. 



DEFINITE DISEASES. 



Tuberculosis. During the last twenty years there has 

 been a very voluminous discussion over the problem of the 

 relation of human tuberculosis to milk, and at all times 

 during this period and even to-day, there has been wide 

 difference of opinion as to the facts in the case. The subject 

 is so complex and many of the points are so obscure that 

 it is, at the present time, almost impossible to make any 

 statements upon the subject which cannot be disputed. 

 Nearly all of the facts and all of the conclusions in regard 

 to the danger of the distribution of tuberculosis from cattle 

 by milk are still under discussion. In the following outline 

 the attempt is made to indicate, as closely as possible, the 

 facts that are definitely known and the conclusions which 

 are legitimately drawn in regard to this matter, but it must 

 be recognized that the subject is as yet so far from final 



