136 THE COMMON SENSE OF THE MILK QUESTION 



from Maryland, where the tuberculin test uniformly 

 reveals a high percentage of infected cattle. It is 

 not suggested, therefore, that the figures here given 

 have any value as showing the comparative distri- 

 bution of the disease, but merely as establishing the 

 fact that a very considerable proportion of cattle 

 are tuberculous. Pearson and Ravenel estimated 

 that, in 1900, 3 per cent of all the cattle in Penn- 

 sylvania were tuberculous.'" They added that "The 

 disease causes more losses than all the other infectious 

 diseases of farm animals that exist in Pennsylvania 

 at this time." " There is good reason for believing 

 that the disease is much more prevalent than would 

 be indicated by the estimate of these two careful 

 observers.* 



In Saxony, no less than 30 per cent of all cattle 

 are believed to be infected by this disease.'^ In 

 Copenhagen, Professor Bang has shown the disease 

 to be very prevalent, making it a matter of vast 

 importance in a country so largely dependent upon 

 dairy farming. Some years ago the percentage of 

 tuberculous animals in Denmark was estimated at 



* Professor Bang pointed out that in large herds of fifty head 

 of cattle and above as many as 60 per cent were tuberculous. 

 He goes so far as to say that, in dealing with large herds in 

 which tuberculosis has existed for many years, it is a waste of 

 time to test with tuberculin the full-grown animals, as they are 

 practicaMy all affected. Quoted in The Suppression of Tubercu- 

 losis, by Professor E. von Behring, p. 5. 



