266 
the influenza iM iioRSfcs. 
authorities, including Barker, Haygarth, Williams, Watson 
and Parks, report instances of the spread of the disease in a 
new locality from persons who have just arrived from the 
infected place. And many veterinarians have adduced in¬ 
stances of its spread in a new region or stable immediately 
after the introduction of a horse from an infected district. 
The present epizootic furnishes cases in point. The malady 
appeared in Syracuse in newly arrived Canadian horses, and 
spread rapidly over the city, while many places around were 
clear. The earliest cases which I have been able to trace in 
Ithaca occurred in the livery-stables of Mr. Jackson, imme¬ 
diately after his return from running a mare in a more 
northern part of the State. In Pittsburg the disease broke 
out first in the livery stables of Messrs. Moreland and 
Mitchell, East Liberty, after the arrival of five or six horses 
from New York City, where the epizootic was then at its 
height. It rapidly spread through the city. From Wash¬ 
ington the first note of alarm was on Oct. 28th, to the effect 
that sick horses had been brought into the city from the 
North, and on Oct. 31st it was reported to be generally pre¬ 
valent. Additional instances of the same kind are to hand, 
but these are submitted in support of the doctrine of the 
presence in the animal body of a specific contagious element, 
capable of a rapid reproduction and diffusion. 
The existence of a contagion being acknowledged, can we 
reach any definite conclusion as to its nature ? Not in the 
present state of science. Here we leave the confines of the 
known and enter on the hypothetical. The prevailing 
theories concerning the virulent matter of specific fevers may 
be resolved into two: that which recognises the microscopic 
spores of fungi and other low forms of vegetable life as the 
infecting principle; and that which seeks the same morbid 
element in the infinitesimal granules of organic matter found 
floating in the air as well as in the fluids and solid structures 
of the diseased body. 
The first-named theory, so strenuously supported by Polli, 
Davaim, Hallier, and others, is liable to the objection, when 
applied to influenza, that no specific vegetable germs have 
been found in the air or blood during its prevalence. Before 
the advent of the prevailing epizootic the writer subjected 
the floating elements in the air from stables and fields to 
miscroscopic examination and continued the investigation 
until the disease was at its height, but without detecting any 
important difference in the floating germs and particles ob¬ 
tained from first to last. This conclusion has been since 
thoroughly substantiated by the investigations of Dr. Wood- 
