CONTAGIOUS PLEURO-PNEUMONE?. 
501 
have been previously occupied by those having pleuro-pneumonia, 
and that the contagion is only virulent when conveyed by the 
living animal.” 
Clement Stephenson, F.P.C.V.S., Inspector for Northum¬ 
berland, in a letter of September 10th, sa} 7 s: “Although I never 
had any doubt as to the so-called experiment at Chicago, it is 
still gratifying to find that it has worked out as we predicted.” 
Professor James McCall, Principal of the Veterinary College, 
Glasgow, Scotland, under date of September 26th, says: “I have 
much pleasure in acknowledging receipt of yours of 2d inst., 
intimating the result of your experiment with the cattle in the 
sheds of the Shufeldt Distillery, and I should have been dis¬ 
appointed had it terminated otherwise. I have for the past 
twenty years maintained that the contagion of pleuro-pneumonia 
is only spread by the living affected animals, and that cohabitation 
is necessary.” 
Professor Thos. Walley, Principal of the Poyal Veterinary 
College, Edinburg, in his letter of September 26th, is more con¬ 
servative, and while he does not deny that the disease can only 
be communicated from the living animal, neither does he affirm 
it, but says: “ One swallow does not make a summer, you know, 
and perhaps if your experiment is repeated the result may be 
very different.” 
Professor J. Wortley Axe, Professor of Pathology in the 
lioyal Veterinary College, London, says in his letter of October 
10th : “ It has always appeared to me that the virus of the disease 
is peculiarly unstable, and to be effective requires to pass directly 
from the respiratory organs of the sick to the healthy, and hence 
it is that cohabitation, or contact of the former with the latter, is 
rendered necessary to the propagation of the disease.” 
So while assertions have been made that the disease has been 
carried in the clothing of attendants, or remained in sheds and 
buildings from which diseased animals have been removed, yet in 
no instance has any authentic proof of this been produced; while 
on the contrary we have the evidence of college principals and 
professors and men which have given years of study to the dis¬ 
ease, and with the single exception of Professor Walley, who is 
