DR. BILLINGS VINDICATED. 
519 
characteristics. Smith neglects to observe that the experi¬ 
ments quoted by Billings were especially selected out of a 
great number. I find it remarkable that Smith should question 
these twelve published experiments of Billings, the value of 
which is beyond doubt. 
The inference (by Smith) that I allowed Billings’ publica¬ 
tions to influence me in the consideration of Salmon’s swine 
plague by no means corresponds with the facts. For 
judging this question I have referred to the publications of 
the Buieauon the assumption that in these official reports the 
most reliable material must be found. 
In regai d to the question as to whether the Salmon swine 
plague germ is an independent cause of a specific disease I 
cannot change my previously expressed opinion. How far I 
am right can best be judged by reading Smith’s publication in 
this journal 
As will be remembered, Salmon, supporting himself on the 
German schweine seuche, distinctly and emphatical asserts the 
existence of an independent plague and at the same time united 
with the hog cholera, which has the same degree of extension 
over the country. 
Judged by the investigations published in the reports of 
the Bureau, we find but proportionately few cases and these 
not free from objections, of the appearance of a disease-pro¬ 
ducing gei m in chronic cases of hog cholera. The conditions 
closely resemble those seen in certain infectious diseases in 
man, where the secondary appearance of pathogenic germs 
has long been observed, without any one asserting them 
to be independent causal moments, or the cause of extensive 
epidemics. 
The last two cases reported by Smith in favor of his swine 
plague do not give evidence which sufficiently excludes the 
concomital existence of hog cholera also. At the same time 
and the same place, several swine are reported to have died 
from the cholera. 
The fact stands for me confirmed that in the five years that 
have passed since the second plague was first announced not 
one single case of an independent appearance of Salmon’s 
i 
