SECRETARY'S REPORT. 13 



It will bo seen that the experiments with this herd are not 

 yet concluded. The above are the facts thus far. 



Conclusion. — It would be rash to draw general conclusions 

 from an experiment so limited. The following are the results 

 thus far obtained : — 



1. Only one animal of the five exposed, became diseased 

 during an observation of eighty days. 



2. The disease did not prevent the mother from bringing 

 forth a healthy calf, which has continued healthy six weeks ; 

 nor has it prevented her from giving good milk. 



3. It is probable the heifer would also have recovered. 



4. In an economical point of view it would have been unwise, 

 so far as this herd was concerned, to kill all the animals as 

 soon as exposed ; whether we have regard to the value of the 

 animals recovered, or the number which apparently became 

 diseased in consequence of exposure. 



These are the conclusion to which a believer in the contagious 

 nature of the disease would assent. . 



A believer in epidemic or local influences as a cause of the 

 disease, would object that the experiments are not conducted 

 at a sufficient distance [six miles] from the place where it is 

 known to be rife ; that pleuro-pneumonia is epidemic among 

 pigs in the immediate vicinity ; that epidemic pleuro-pneumo- 

 nia among human beings has been known to extend over the 

 whole of New England and New York. In fine, that the herds 

 of Waltham are subject to similar influences as those in Cam- 

 bridge, differing in degree. 



These experiments have been undertaken not without con- 

 siderable expense and trouble ; they are offered as a contribu- 

 tion to our knowledge of a most important disease among cattle, 

 with the hope that they may be continued until definite results 

 shall be arrived at, not only as to its contagion or non-contagion, 

 but also with regard to other points interesting in an econom- 

 ical point of view, and not less so as it bears upon the study of 

 comparative pathology. I have the honor to be. 



Your Excellency's obedient servant, 



Morrill Wyman. 

 Cambridge, December 23, 18G3. 



