INFLAMMATION OF THB LUNGS. 
231 
ill by rigor. The horse is cold all over ; this, however, soon 
passes oti’, and we have general warmth, or heat of the skin 
above the usual temperature, hut accompanied hy coldness of the 
extremities —intense deathy coldness. This is a perfectly diag¬ 
nostic symptom : it will never deceive you. It is an early 
symptom ; it is found when there is little or no constitutional 
disturbance,— when the pulse is scarcely affected, and the flanks 
heave not at all, hut the horse is merely dull and off his feed. 
It is that by which you will mark the progress of the disease 
when others scarcely suspected its existence. The blood is de¬ 
termined to the inflamed part—it is congested in the lungs—a 
diminished portion of it passes the left side of the heart—it 
scarcely reaches the extremities, or it is not ^ufliciently arterial- 
ized, and little heat is consequently extricated in its change to 
venous blood. 
The pulse is not always at first much increased in rapidity, and 
it is rarely or never hard : it is obscure, oppressed. The heart is 
labouring to accomplish its object—the circulation through the 
lungs is impeded—the vessels are engorged—they are ruptured— 
blood is extravasated into the air-cells—it accumulates in the 
right side of the heart—and in the larger vessels, and in the 
venous circulation generally, there is a mechanical obstruction, 
which the heart has not power to overcome : hence the obscure, 
oppressed pulse,—the ineffectual attempt to urge on the blood ; 
and hence, too, the remarkable result of bleeding in inflamma¬ 
tion of the lungs—for the pulse becomes rounder, fuller, quicker. 
When blood is abstracted, a portion of the opposing force is 
removed, and the heart, being enabled to accomplish its object, 
the pulse is developed. 
It is only, however, in the early insidious stage that the flanks 
are occasionally quiet: if the compressibility of the lungs is di¬ 
minished by the thickening of the membrane, or the engorgement 
of the vessels, and the filling of the cells, it will be harder work 
to force the air out; there must be more evident effort, and that 
which cannot be accomplished by one effort is attempted over 
and over again. The respiration is quickened — laborious; the 
inspiration is lengthened, in order to lessen the pain which the dis¬ 
tending of the vessels occasions ; the expiration is rapid, in order 
to get rid of the pain caused by the state of distention ; and when,, 
after all, the lungs cannot be compressed by the usual means, every 
muscle that can be brought to bear upon the part is called into ac¬ 
tion. Hence, the horse will not lie down, for he can use the muscles 
of the spine and the shoulder with most advantage as he stands : 
hence, too, the very peculiar stiffness of position—the disinclina^ 
tion to more. There are various muscles whose action can be 
