e which
have arrived in the spring; and it almost always happens that the years
in which it shows itself most generally are those in which the weather
was most unfavorable while the cattle were on the road. The journey is
performed by two different routes,--through Lorraine and through
Champagne,--and the disease frequently appears in cattle that have
arrived by one of these routes. The manner in which the beasts are
treated, on their arrival, may contribute not a little to the
development of the malady. These animals, which have been driven long
distances in bad weather, and frequently half starved, arrived famished,
and therefore the more fatigued, and some of them lame. Calculating on
their ravenous appetite, the graziers, instead of giving them wholesome
food, make them consume the worst that the farm contains,--musty and
mouldy fodder; and it is usually by the cough, which the eating of such
food necessarily produces, that the disease is discovered and first
developed.

"Is chronic pleuro-pneumonia contagious? The farmers believe that it is,
and I am partly of their opinion. When an animal falls sick in the
pasture, the others, after his removal, go and smell at the grass where
he has lain, and which he has covered with his saliva, and, after that,
new cases succeed to the first. It is true that this fact is not
conclusive, since the disease also appears in a great number of animals
that have been widely separated from each other. But I have myself seen
three cases in which the cattle of the country, perfectly well before,
have fallen ill, and died with the same symptoms, excepting that they
have been more acute, after they have been kept with cattle affected
with this disease. This circumstance inclines me to think that the
disease is contagious; or, at least, that, in the progress of it, the
breath infects the cow-house in which there are other animals already
predisposed to the same disease. I am induced to believe that most of
the serious internal diseases are communicated in this manner, and
particularly those which affect the organs of respiration, when the
animals are shut up in close, low, and badly-ventilated cow-houses."
[_Rec. de Med. Vet. Mai, 1833._]

No malady can be more terrible and ruinous than this among dairy-stock;
and its spread all over the country, together with its continuance with
scarcely any abatement, must be attributed to the combination of various
causes. The chief are: _first_, the