CHRONIC PLEURO-PNEUMQNIA. 
503 
cles. Beside the old adhesions, many false membranes are found, 
which, although thick, are of recent date. The pleura is not 
much reddened, but its thickness in some points, the adhesion 
at others, and frequently the effusion of a serous fluid, suffi¬ 
ciently prove that it has participated in the inflammatory action. 
The trachea and the bronchi are slightly tinged with red on the 
exterior, and the right side of the heart is gorged with blood. 
In a subject in which, during life, I could scarcely feel the 
beating of the heart, I found the whole of the left lobe of the 
lung adherent to the sides, and completely hepatized. In another 
that had presented no sign of disease of the chest, and that for 
some days before its death vomited the little fodder which he 
could take, the whole of that portion of the oesophagus which 
passed through the chest was surrounded with dense false mem¬ 
branes, of a yellow hue, varying from light to dark, and being 
in some parts more than an inch in thickness, and adhering 
closely to the muscular membrane of the tube, without allowing 
any trace to be perceived of that portion of the mediastinal 
pleura on which this unnatural covering was fixed and developed. 
Causes .—It is difficult to discover the real cause of this dis¬ 
ease. The graziers imagine that the animals bring it with them 
from their native country ; and the traces of chronic disease 
that are found in them when they are slaughtered soon after 
their arrival singularly confirm this opinion. It is well known 
that cattle which have been worked hard are often attacked by dis¬ 
eases of the chest, that are not got rid of without leaving 
some interior lesions; and the breeders know their interest too 
well not to get rid of those animals as soon as possible that 
have been affected with complaints of the chest. The manner 
in which the journey is performed contributes much to revive 
the old disorder; and I am confirmed in this idea, when I see 
that the cattle bred in the district, and which are not worked, 
are rarely, if ever, attacked by this chronic pleuro-pneumonia. 
Other circumstances also contribute to support this opinion. 
The cattle purchased in Tranche Comte are brought to Avesnes 
at two periods of the year—in the autumn and in the spring. 
Those which are brought in the autumn are much more subject 
to the disease than those which arrive in the spring; and it al¬ 
most always happens, that the years in which the disease shews 
itself most generally are those in which the weather was most 
unfavourable while the cattle were on the road. The journey is 
also performed by two different routes—through Lorraine and 
Champagne; and the disease frequently appears only in the 
cattle that have arrived by one of these routes. The man¬ 
ner in which the beasts are treated, on their arrival, may contri- 
