for recovering Perfons apparently drowned. 417 
had been thrown in by the former, without mixing them 
together. The muzzle of thefe bellows was fixed into 
the trachea of a dog, and by working them he was kept 
perfectly alive. While this artificial breathing was 
going on, I took off the Jlernum of the dog, and ex- 
poled the lungs and heart; the heart continued to acft 
as before, only the frequency of its a&ion was confi- 
derably increafed. I then flopped the motion of 
the bellows, and the heart became gradually w-eaker, 
and lefs frequent in its contraction, till it left off mov- 
ing altogether: by renewing my operation, the heart 
began again to move, at firfi: very faintly, and with 
longer intermifiions ; but, by continuing the artificial 
breathing, the motion of the heart became again as fre- 
quent and as ftrong as before. This procefs I repeated 
upon the fame dog ten times, fometimes Hopping for 
five, eight, or ten minutes. I obferved, that, every time 
I left off working the bellows, the heart became ex- 
tremely turgid with blood, and the blood in the left fide 
became as dark as that in the right;, which was not the 
cafe when the bellows were working. Thefe fixa- 
tions of the animal appear to me exactly limilar to 
drowning. 
The lofs of life in drowned people has been accounted, 
for, by fuppoling that the blood, damaged by want of the 
adtion of the air in refpiration, is lent, in that vitiated 
Hate, to the brain and other vital parts ; by which means 
the nerves lofe their effebt upon the heart, and the heart 
in confequence its motion. This, however, I am fully 
convinced is falfe: firff, from the experiments on the 
dog, 
