the spinal marrow on the action of the heart in fishes. 95 
and slower, there being an interval of one second between the 
contraction of the auricle and ventricle. From the time of 
exposing the heart no action was perceptible in the branchial 
artery ; it remained of a blue colour, and turgid with blood 
from its first exposure. 
At three hours and three quarters, the pulsations of the 
heart were only nine in a minute. The interval between the 
contraction of the auricle and ventricle three seconds. 
At four hours, the pulsations were seven in a minute, the 
interval between the contraction of the auricle and ventricle 
four seconds. 
At four hours and a quarter, the pulsations were seven in 
a minute ; the interval between the contraction of the auricle 
and ventricle five seconds. 
At four hours and a half, seven in a minute ; the interval 
between the contraction of the auricle and ventricle six 
seconds. 
At four hours and three quarters, seven in a minute ; the 
auricle and ventricle acting together. 
At five hours, seven in a minute, the interval between the 
contraction of the auricle and ventricle, one second and a 
half. 
At six hours, the contraction of the auricle seven in a mi- 
nute, the action of the ventricle hardly perceptible. 
At six hours and a quarter, the contractions of the auricle 
weak : seven in a minute. 
At six hours and a half, the auricle ceased to contract ; and 
after this time, no stimulus produced the smallest action in 
any part of the heart. This experiment was suggested by a 
notice taken from Dr, Wilson Philip’s paper, published in 
