380 BOARD OF AGEICULTURE. [Pub. Doc. 



strated, other animals, when subjected to abnormal conditions, 

 will so far vary the results as to materially complicate the prob- 

 lem of determining the existence of the disease. 



This scientific method, it must be remembered, is compara- 

 tively new ; and, while it has been carefully studied in its nor- 

 mal aspects and under more ordinary conditions, the nature and 

 effect of abnormal conditions cannot as yet be thoroughly tab- 

 ulated. Hence it is that while in the opinion of this Board 

 tuberculin is a reliable test under ordinary conditions, extra- 

 ordinary conditions, frequently unknown to the person apply- 

 ing it, so far complicate the matter as to cause errors to creep 

 into a certain extent, which errors, in the opinion of tlie Board, 

 are not due to the tuberculin, but to the unapprecialile cir- 

 cumstances. While this agent as a test of the existence of 

 tuberculosis has been used to a considerable extent by other 

 scientists and l)oards doing the same work, under normal con- 

 ditions, l)ut little is known as to the effect upon it of the ab- 

 normal conditions met with at these markets ; and the Board 

 cannot, therefore, rely upon the researches of others, but must 

 depend entirely upon its own experience in the field in giving 

 to these extraneous circumstances their proper place in deter- 

 mining the result in any given case. There has been no field 

 where the effect of the environment has been so much felt as in 

 the matter of the application of this test to neat stocli brought 

 into the stock yards at Brighton and Watertown. 



The cattle whicli are sold at these marlcets are not resident 

 cattle, but are brought to it from more or less distant jjoints, a 

 great proportion of them coming from without the limits of the 

 Commonwealth. As these cattle are brought there for the pur- 

 pose of sale, it goes without question that they are not delivered 

 at the market except at as near to the time of sale as circum- 

 stances will permit, the owners not desiring to incur any una- 

 voidable expense for care and food. The commission have 

 therefore endeavored to arrange that the quarantine shall cover 

 the shortest possible period of time that an application of this 

 test will permit. These cattle are collected from different locali- 

 ties and brought together for the first time. They have been 

 put into crowded cars, have suffered the excitement attending 

 an unusual journey, have prol)ably received their food and 

 Water at irregular periods, and iu every possible way have been 



