462 
ANIMAL PATHOLOGY. 
at least seven ounces. During the jDrocess of injection the animal 
heaved convulsively, and was very sick. The difficulty of breath¬ 
ing increased—it was painful to behold. In order to relieve it, 
and as another interesting experiment, the anterior portion of the 
third ring of the trachea was removed, but without any marked 
advantage. 1 would rather say, that the labour of respiration 
was aggravated. On being liberated, he appeared to be very 
much weakened—he sat on his haunches leaning against the wall, 
and his fore-paws continually slipping from under him. I 
watched him during two hours. He was gradually sinking, and he 
was found in the morning nearly slipped down, his head resting 
on the ground, and quite dead: he must have died without a 
struggle. 
Magendie conducted a similar experiment. His patient was a 
large mastiff. He laid bare the jugular vein, and, making an 
incision into it, abstracted about a pint of blood, while at the 
same time, through another incision situated lower down in the 
vein, he introduced warm water. On the whole, beside the 
pure blood that was taken away, there escaped about ten or 
twelve ounces of mingled blood and water. The dog, that before 
the experiment had been exceedingly violent, was now quite 
calm, and on being liberated curled himself up as it were to sleep ; 
but he did not close his eyes. Five hours after the injection he 
began to suffer great difficulty of respiration, which continued to 
increase for half an hour, and then he died. During the whole 
of the previous time he was altogether calm. He was destroyed, 
as was the poor terrier whose case I have just related, by infarc¬ 
tion of the lungs, the whole tissue of which was filled with aque¬ 
ous blood. 
In one case I had recourse to the transfusion of blood. The 
patient was a large mastiff bitch, with dumb madness, and toler¬ 
ably manageable. Eight ounces of blood were withdrawn, and 
replaced by nearly a similar quantity of that fluid from another 
mastifl" that I happened to have at that time in my hospital. A 
slight shivering fit immediately followed the transfusion, and this 
was succeeded by increased brightness of the eyes, and, as I 
thought, a slight retraction of the tongue. The breathing w'as 
quickened—it was to a certain degree laborious; and the pulse 
was accelerated eight or ten beats in the minute. In less than 
six hours this had all passed over, and she was evidently weaker 
than before the experiment. 
Ten hours after this experiment six ounces more of blood were 
withdrawn, and replaced by nearly an equal quantity from the 
dog that furnished the fluid for the first transfusion. The coun¬ 
tenance again brightened, and the respiration and the pulse were 
