80 
3. That a double pulsation or action may be felt on deep pressure 
over the tumour. 
4, That when M. Groux suspends his respiration, the tumour ac- 
quires a volume far beyond what could be supposed to be attainable by 
the pulmonary artery, even at its origin. 
By a similar process of investigation we conclude that it is not pro- 
duced by the diastole of the aorta. This conclusion is strengthened by 
the observation that, on making pressure in the inter-clavicular space, 
the pulsations of the aorta can be felt giving the usual phenomena,—the 
sphygmoscope also showing the want of synchronism between the beat 
of the tumour and that of the aorta, the fissure preceding the latter by 
a distinct interval. 
We hence conclude that this remarkable pulsation can be only that 
of the right auricle. Its general character and appearances coincide 
remarkably with those which belong to the auricular actions as seen in 
vivisections; and all its phenomena are explicable on this hypothesis. 
For the sake of clearness we shall here recapitulate the reasons which 
lead us to conclude that the oval body is the right auricle. 
1st. Its situation, which is neither that of the base of the ventricles 
nor the arch of the aorta. 
2nd. The progressive, or, as it were, vermicular action of the pul- 
sation. 
8rd. Its singleness of sound. 
4th. The sensation which it conveys of being a cavity with thin 
walls. 
5th. Its remarkable enlargement when respiration is suspended. 
6th. Its precedence of the ventricular impulse. 
Rozert Harrison. 
Rosert Law. 
Wri114m Stroxzs. 
Rosert D. Lyons. 
Dr. Law said, that, as a member of a profession peculiarly interested in 
the advancement of the science of Physiology, he felt that he ought to 
express his obligations to the Academy for the readiness with which it had 
acceded to the suggestion of appointing a Commission to inquire into the 
case of M. Groux, which presented so favourable an opportunity of m- 
vestigating some of the most important phenomena of the circulation and 
the heart’s action. In the conduct of the Academy on this occasion 
Dr. Law recognised an admission that Physiology had its place amongst 
those sciences that it was intended to promote, and that it was not its 
fault that communications upon so important and interesting a science 
were so rare in the Academy, but rather reflected on those members 
from whom such communications might have been expected. Dr. Law 
observed that Physiology was the basis of medicine as a science; that 
we acquired our knowledge of it by observation and experiment on 
living animals. Observation taught us the phenomena which bodies 
