32 BOARD OF AGRICULTURE. 



that the cattle bringing that disease north do not fall victim* 

 to it themselves ? 



Dr. Salmon. If I attempt to answer the question, I will 

 have to do it by giving an opinion merely, because I do not 

 pretend to understand it myself. It is true that young ani- 

 mals taken to the South contract the disease in a mild form. 

 It seems to have but slight eifect upon them : you will notice 

 a little fever and loss of appetite for a few days, and they re- 

 cover, and from that time on, they have immunity from the 

 disease, — as great as the immunity from measles after the 

 first attack. Now, whether all the young cattle in the South 

 have a mild attack of this disease when calves, or not, I am 

 unable to say, but whatever may be the explanation of the 

 IDhenomenon, it is very certain that the cattle at the South 

 do resist the germs of this disease in a most wonderful man- 

 ner, even more completely than northern cattle which have 

 o-one there and had an attack of the disease. 



The Chairman. If the cattle are brought from the South, 

 they communicate the disease, and more cattle die in the 

 region to which they are brought, from the infection, than 

 the original cattle themselves. 



Dr. Salmon. The original cattle seldom sicken at all un- 

 less they have been driven a long distance and are very much 

 exhausted. They infect the pastures by grazing or running 

 over them, and any native cattle which run upon those pas- 

 tures afterwards are liable to the infection. 



Question. .Will an animal being infected from direct con- 

 tact with this disease re-transmit it to a second animal ? 



Dr. Salmon. There is hardly a case that has happened 

 at the North where it has been suspected that such a method 

 of transmission occurred. I doubt, in fact, if there has ever 

 been known a case at the North where a second northern ani- 

 mal has contracted the disease from the first one. Indeed, 

 animals never seem to contract the disease directly from 

 other animals, but from pastures on which animals from the 

 South have lain or crossed. Indeed, along the border-line 

 of this district in the South, it very frequently happens that 

 an animal from the uninfected district comes upon the infect- 

 ed district, and there takes the disease, and that animal. 



