252 
Gr. ARCHIE STOCKWELL. 
under the knife. The average duration of pulsations for the 
series was 257 seconds after the heart was exposed, which, 
allowing thirteen seconds for removal from the jar and vivi¬ 
section, would make a total of four and one-half minutes— 
ample time, if such had been desired, to institute measures 
for resuscitation. 
These experiments, and others that have been made by 
various individuals upon cats, dogs, hares, guinea-pigs, etc., 
in which varying quantities of stronger ether (sufficient to 
induce profound anaesthesia, however,) were respired, intro¬ 
duced into the rectum and colon, or injected into the perito¬ 
neum, fully vindicating the principle propounded by Dr. 
Snow, that fatality rarely, if ever obtains, save as the result 
of supersaturation of the economy ; that is to say, that there 
must be arrest of respiration, whereby the blood is deprived 
of its necessar}^ oxygen, the latter being replaced by ether 
vapor. If this premise be true, as it certainly seems to be, 
cardiac arrest can never occur save as a sequel to pulmonary 
paralysis, and even where there is ether narcosis tending to 
fatality, there is usually a margin wherein it is possible in 
most instances to resuscitate the patient. Herein is an im¬ 
measurable factor for safety, such as can secure to chloroform 
only in very rare and unusual cases. There is, perhaps, an 
exception, or at least partial exception, to be taken as to 
ether, that, however, does not apply to anaesthesia for surgi¬ 
cal purposes, but to the physiological laboratory, since, as 
one experiment of Anstie’s seems to prove, an animal intro¬ 
duced bodily into an atmosphere wholly saturated with ether 
vapor, and therefore with no opportunity for elimination, ow¬ 
ing to the overloading of the circulation, due to the absence 
of oxygen, may succumb to apparently coincident or simul¬ 
taneous pulmonary and cardiac arrest. 
For a long time it was believed that the circulation and 
respiration were interdependent, and so the former made the 
basis of watchfuluess in ether as well as chloroform 
anaesthesia; and even yet this is the procedure of many 
practitioners. Such, however, must necessarily prove a false 
guide and a “ broken reed ” to lean upon, since it not infre- 
