624 REVIEW— ON THE EPIZOOTIC IN CATTLE. 
tinues to do so until the blood becomes impoverished and poisoned: 
it is then that the system becomes deranged, the digestive process 
impaired, and fever established. The skin adheres to the ribs, and 
there is tenderness along the spine. Manipulation of the trachea, 
and percussion applied to the sides, cause the animal to evince 
pain. Although the beast may have been ill only three days, the 
number of pulsations is generally about seventy per minute ; but 
they are sometimes eighty, and even more. In the first stage, the 
artery feels full and large under the finger ; but as the disease runs 
on, the pulse rapidly becomes smaller, quicker, and more oppressed. 
The breathing is laboured, and goes on accelerating as the local 
inflammation increases. The fore extremities are planted wide 
apart, with the elbows turned out in order to arch the ribs, and 
form fixed points for the action of those muscles which the animal 
brings into operation to assist the respiratory process. In pleuro- 
pneumonia, the hot stage of fever is never of long duration. The 
state of collapse quickly ensues, when the surface-heat again de- 
creases, and the pulse becomes small and less distinct. We have 
now that low typhoid fever so much to be dreaded, and which 
characterises pleuro-pneumonia in common with other epizootics. 
Auscultation, when directed towards the situation of the inflamed 
spots, fails to perceive the low rustling murmur of the healthy 
lungs, and detects a crepitating rale, which, as the case advances 
towards an unfavourable termination, becomes duller, and at last is 
altogether inaudible. Percussion indicates a dull deadness of 
sound, which the experienced ear cannot fail to distinguish from 
the clear, free resonance of the healthy lung. 
The horse labouring under pleuro-pneumonia, or, indeed, any 
pulmonary disease, will not lie down ; but, in the same circum- 
stances, cattle do so as readily as in health. They do not, how- 
ever, lie upon their side, but couch upon the sternum, which is 
broad and flat, and covered by a quantity of fibro-cellular sub- 
stance, which serves as a cushion ; while the articulation between 
the lower extremities of the ribs and their cartilages admits of 
lateral expansion of the thorax. In this position cattle generally 
lie towards the side principally affected, thus relieving the sounder 
side, and enabling it to act more freely. There is sometimes a 
shivering and general tremor, which may exist throughout the 
whole course of the disease. This seems to be dependent upon the 
impurity of the blood, its unequal distribution, its collecting around 
the internal organs, and its ceasing to be duly circulated through 
the capillaries of the skin. These chills and rigors do not neces- 
sarily prove the presence of inflammation, but merely shew a tend- 
ency to it : they are entirely different from the general coldness 
of the surface usually apparent in the latter stages of the disease. 
