ON THE CAUSES AND SPREAD OF INFLUENZA. 587 
escape. Very strong constitutioned animals, and such as have 
no predisposition to this disease, are spared. 
Traces or isolated appearances of this disease are to be met 
with at all seasons, but chiefly in autumn, and then it principally 
attacks horses that, from some cause or other, have been very 
much confined to their stables. I do not mean to say that those 
which are only brought into the stable at night, or even those 
which are left out in the meadows, escape; for such is not the 
case, although instances of horses that live constantly in the open 
air being attacked with influenza are rarely heard of. 
I have seen this disease prevail to a frightful extent among 
cavalry horses while in the barracks or depots, but it rarely ap- 
pears among troops while on the march, or among those horses 
in barracks that are regularly turned out during a certain portion 
of the day. It is only where a great number of horses are con- 
fined together in stables, from morning until night, that its ravages 
are so fearful. 
The air in such stables becomes heavy with animal emana- 
tions, especially where the horses are only taken out for a short 
period now and then. In such stables there is seldom any means 
of obtaining a regular change of air, and the animals constantly 
inhale the floating miasm, and its poisonous influence becomes * 
manifest in the development of influenza. 
In the beginning of Oct. 1841, seventy-six cavalry horses 
were delivered at the barrack depot, at B’arenklau, where the in- 
fluenza was at that time raging frightfully. There were three 
troops then at the depot, and among these the horses were equally 
divided, twenty-six being reserved for B’arenklau. These latter 
were turned into a large meadow a quarter of a mile distant from 
the winter quarters, and were there treated exactly the same as 
the animals which had been previously there. Although only four- 
teen days before, the disease had broken out among the numerous 
horses assembled there, and even spread to the winter quarters, 
and the straw-yard, and attacked sixteen ponies which stood in a 
dark stable — notwithstanding all this, these twenty-six cavalry 
horses escaped, while those divided among the troops, and the 
greater part of those which had been there previously, suffered 
severely from influenza. What is still more remarkable is, that at 
the same time no other horse was suffering from influenza in the 
whole of the neighbourhood ; hence the disease could not have 
been brought into the depot in that manner, and must have arisen 
from the inhalation of the miasm of which I have before spoken, 
and which I consider to be one of the chief predisposing and 
inducing causes of influenza. 
Magasin fur die gesammte Thierheilkunde, 1843, p. 207. 
