REVIEWS. 
563 
progress of the disease, but it 
appears also to have produced a 
conviction in the minds of many 
veterinarians who wavered on the 
subject, that pleurisy, independent 
and distinct from pneumonia, may 
and occasionally does exist in the 
horse ; and that therefore, in a syste- 
matic point of view, it is proper to 
consider it under the distinct heads 
of pneumonia and pleuritis , to which 
also I would add that of pneumo- 
pleuritis, as no one will deny that 
the character this implies is by far 
the most usual form of the disease ; 
and he who is fortunate enough to 
treat this successfully may leave the 
other two to his neighbours. 
Pneumonia or inflammation of the 
substance of the lungs. — Under this 
I shall treat in detail on the causes, 
symptoms, and cure, as a type 
applicable to the three varieties ; 
aud premise the account by observ- 
ing, that when we consider how 
totally we have removed the horse 
from a life of nature to one of art, in 
which the lungs, although more 
important than most, and certainly 
more vascular than any other organs, 
are subjected in an extraordinary 
degree to the extremes of exertion 
and temperature, we cannot be sur- 
prised that they should in a greater 
degree form the seat of acute in- 
flammation. 
Causes. — The predisposing may be 
looked for in constitutional plethora, 
occasioned by high feeding, hot 
clothing, stabling with high tem- 
peratures, and constant accelerated 
exercise, all which render the lungs 
more susceptible to congestion, and 
less able to resist the effects of it. 
The proximate are numerous ; among 
them alternations between heat and 
cold are probably the most common ; 
and we have more reason to believe 
that it is the alternations themselves, 
as we find that horses bear the 
extremes of both heat and cold, by 
their geographical distribution, with 
equal impunity. Under this view 
we are led to conclude, as well by 
reason as by fact, that the alterna- 
tions being the active agents, the 
injurious consequences are likely to 
have produced a conviction in the 
minds of many veterinarians who 
wavered on the subject, that pleurisy, 
independent and distinct from inflam- 
mation of the lungs, may and occa- 
sionally does, exist in the horse ; and 
that therefore, in a systematic point 
of view, it is proper to consider the 
various chest affections under dis- 
tinct heads ; to which also may be 
added that of pleuro-pneumonia, or 
inflammation of the lungs, and pleura, 
existing at one and the same time ; 
as no one will deny that this is by 
far the most usual form of disease. 
Inflammation of the substance of 
the lungs , or pneumonia. — W hen we 
consider how totally we have removed 
the horse from a life of nature to 
one at art, in which the lungs, more 
vascular than any other organs, are 
subjected in an extraordinary degree 
to the extremes of exertion and 
temperature, we cannot be surprised 
that they should in a great measure 
form the seat of acute inflammation. 
Causes. — The predisposition may be 
looked for in constitutional plethora, 
occasioned by high feeding, hot 
clothing, stabling with high tempera- 
tures, and by accelerated exercise; 
all which render the lungs more sus- 
ceptible to congestion, and less able 
to resist the effects of it. Among 
the various causes alternations 
between heat and cold are probably 
the most common ; and we have the 
more reason to believe that it is the 
alternations themselves which pro- 
voke the disorder, as we find that 
horses bear the extremes of both 
heat and cold, in different countries, 
with seeming impunity. Heat sud- 
denly applied may be supposed to 
heighten the circulation generally , 
and produce congestion immediately 
within the lungs. Cold suddenly 
