78 
DISEASES OF THE RESPIRATORY ORGANS, 
the conventional mode. We have not succeeded in assigning 
precise limits to any one of the forms which the disease 
assumes. 
From the first appearance of “common cold” we have 
traced the mucous irritation extending from the nasal mem¬ 
brane to the bronchial tubes, even to their minutest ramifica¬ 
tions. Associated with these conditions we have found 
deposits in the lung tissue; and further, extensive alterations 
of the structure of the liver. 
Diagnosis in such cases as those we have been considering 
must inevitably be vague; and hence the convenience of 
such terms as “influenza/* “bronchitis/’ “low fever/’ and 
“bilious fever/’ expressions which may be liberally inter¬ 
preted, and are yet sufficiently exact to satisfy the non-pro¬ 
fessional inquirer to whom an exposition of the complica¬ 
tions of disease would prove embarrassing, rather than in¬ 
structive, even supposing the whole of the elements were 
familiar to the practitioner; but instead of his being able to 
see at one view the entire state of disease the symptoms often 
only assist him to a suspicion, or still worse, mask the im¬ 
portant malady completely. 
After a careful post-mortem examination has exposed ail the 
morbid changes, it would still be very difficult to give a name 
to the*disease expressing all its characters; what term, for 
example, would indicate irritation of the mucous membrane 
of the respiratory tubes, the stomach and intestines with de¬ 
posits in the lung structure, effusion into the pleural sacs in 
association with fatty degeneration of heart and liver? and 
yet all these are frequently co-existent in animals that pre¬ 
sented no indications of disease previous to the catarrhal 
attack ; if we except the fact of their being, as dealers’ horses 
generally are, in a plethoric condition. 
Allusion to diseases of heart and liver may possibly seem 
out of place when discussing affections of the respiratory 
system; the connexion between the two being by no means 
obvious, and the two organs in question being of sufficient 
importance to merit a separate notice. Our only defence is 
found in the fact of the very common association of such 
apparently distinct affections : fatty disease of nearly all the 
organs in the body is not remarkable in overfed animals; of 
these organs the heart and liver would certainly exercise a 
more important influence than either of the others likely to 
be similarly affected; but it seems that only when the system 
is deranged by an attack of a febrile character that these 
organic changes cause such disastrous consequences, inducing 
an irregularity of the circulation on the one hand, and leading 
