32 8 MILK AND THE PUBLIC HEALTH chap. 



The bacilli are retained in the sac, but their toxins pass 

 through the dialysable substance of the sac and immunise the 

 animal. The technique is said to be quite simple and the 

 results so far satisfactory. 



These vaccination methods are extremely interesting, but 

 it appears that no results are yet available, proving that they 

 are of permanent value in eradicating bovine tuberculosis. 



ISTiven,^ from a consideration of the whole subject, concludes 

 that " no proposal which has not for its declared aim the 

 extirpation of bovine tuberculosis contains that element of 

 ultimate profit which justifies large present sacrifices.'' He 

 summarises the proposals he puts forward to control bovine 

 tuberculosis as follows : 



1. The country to lend money at a low rate of interest to 

 landowners, on sufficient security, to enable them to carry out 

 necessary works of construction or reconstruction. 



2. The country as a whole to provide the veterinary staff 

 required and the tuberculin, as well as to make good losses 

 involved in the first instance in eliminating tuberculosis from 

 herds. 



3. The maintenance of non-tuberculous herds to be com- 

 pulsory, and the cost of any renewal of stock to fall upon the 

 farmer. 



4. In return for their contribution to the agricultural 

 interest, consuming communities should have rights of control 

 over the production of milk which they consume. 



5. Milk dealers in entering into contracts should be 

 obliged to satisfy themselves that their milk is produced under 

 reasonably healthy conditions. 



The control of bovine tuberculosis has been taken up with 

 vigour and enthusiasm in many of the States comprised in the 

 United States of America. For a critical consideration of the 

 different methods practised, the enactments framed, and the 

 results obtained, the very valuable Eeport to the Local 

 Government Board by Dr. Eastwood should be consulted. 

 Eastwood's main conclusions upon this subject are as follows : 



1. It is imperative, in the interests of agriculture, that 

 dairy cows with advanced or generalised tuberculosis, or with 

 tuberculosis of the udder, should be destroyed. 



' British Medical Journal, Sept. 11, 1909, p. 699. 



