of Edinburgh, Session 1878-79. 101 
searches seemed to the Committee to warrant the following con- 
clusions : — 
1. Both chloroform and ethidene administered to animals have a 
decided effect in reducing the blood-pressure, while ether has no 
appreciable effect of this kind. 
2. Chloroform reduces the pressure much more rapidly and to a 
greater extent than ethidene. 
3. Chloroform has sometimes an unexpected and apparently 
capricious effect on the heart’s action, the pressure being reduced 
with great rapidity almost to nil, while the pulsations are greatly 
retarded or even stopped. The occurrence of these sudden and 
unlooked-for effects on the heart’s action seems to be a source of 
serious danger to life, all the more that in two instances they 
occurred more than a minute after chloroform had ceased to be 
administered, and after the recovery of the blood- pressure. 
4. Ethidene reduces the blood-pressure by regular gradations 
and not, so far as observed, by these sudden and unexpected 
depressions. 
5. Chloroform may cause death in dogs either by primarily para- 
lysing the heart or the respiratory mechanism. The variations in 
this respect seem to depend to some extent on individual peculiari- 
ties of the animals ; in some the cardiac centres are more readily 
affected, in others the respiratory. But peculiarities in the condi- 
tion of the same animal very probably have some effect in deter- 
mining the vulnerability of these two centres respectively, and they 
may both fail simultaneously. 
6. In most cases respiration stops before the heart’s action, but 
there was one instance in which respiration continued while the 
heart had stopped, and only failed a considerable number of seconds 
after the heart had resumed. 
7. The use of artificial respiration was very effective in restoring 
animals in danger of dying from the influence of chloroform. In 
one instance its prolonged use produced recovery even when the 
heart had ceased beating for a considerable time. 
8. Under the use of ethidene there was on no single occasion an 
absolute cessation either of the heart’s action or of respiration, 
although they were sometimes very much reduced. It can there- 
fore be said that, though not free from danger on the side of the 
o 
VOL. X. 
