210 BOARD OF AGRICULTURE. 



to a specific virus introduced into the system, resorted to a series of 

 experiments on animals to test the question. He was the first to 

 demonstrate the contagiousness of tuberculosis by inoculation. Rab- 

 bits and guinea-pigs were selected, and the muteriul employed was 

 from the human lung. Inoculations were made in various parts of 

 the body, but the results were uniform and of a serious character. 

 Many of the creatures died, others, lingering in a depressed state, 

 were killed, when well-marked tubercular deposits were found in all, 

 especially in the lungs, and with more or less infiltrations in the other 

 organs, thus showing that the disease had been transmitted. 



These results, which gave him so much renown as a pathologist, led 

 him to experiment with tubercular matter from other animals. De- 

 sirous, therefore, of testing the nature of the disease in cattle, he 

 inoculated a rabbit with matter from a cow. The animal became 

 emaciated, and in six weeks was destroyed. Its lungs were filled 

 with hard, tubercular masses, and some of them had taken on a 

 cheesy aspect in the center. The other organs of the bod}' were 

 affected in a similar manner as those in the previous experiments. 

 Hence he concludes that bovine phthisis is identical with thai of man. 



Dr. Villemin has likewise demonstrated that the tuberculous mat- 

 ter produced artificially by inoculation possesses the same power of 

 transmissibilit}' as when the malady arises spontaneously, — thus 

 proving conclusively' that in tubercle resides a special germ which 

 does not lose its identity by several removes, no more than that of 

 small-pox. 



This view of the subject is corroborated by the pathological re- 

 searches of Dr. Lionel Beale of London, the celebrated microscopist, 

 who declares that tubercle is a minute particle of living matter, and 

 if inoculated under favorable circumstances it is almost sure to grow, 

 multiply, and produce other morbid cells like that from which it was 

 derived, though he doubts their vegetable origin. And furthermore, 

 Villemin has always considered tuberculosis a specific malad}-, for he 

 found that a very small wound and an inconsiderable quantity of 

 matter used was a manifest proof that the intensity of the disease is 

 independent of the quantity of the matter inoculated, and that the 

 number and extent of the internal lesions have no relations to those 

 at the seat of puncture. A disease, therefore, that can be trans- 

 mitted from one animal to another by inoculation and thus the iden- 

 tical germs reproduced is, strictly speaking, contagious. 



