ON THE MOTIONS AND SOUNDS OF THE HEART. 175 
several points in dispute amongst physiologists of authority, 
which were not investigated by those Committees, and which 
seemed to the Reporter yet unsettled, and at the same time 
important enough to call for direct experimental investiga- 
tion. The following are the principal of those undecided 
questions :— 
1. With respect to the rhythm of the motions of the auri- 
cles and ventricles, several living distinguished physiological 
writers appear to hold, that those cavities act in strict alterna- 
tion with each other, and not continuously or in immediate 
succession, the auricles being first always in systole and dia- 
stole, and the ventricular actions being last before the Rest, as 
described by Steno, Harvey, Lancisi, Haller, Senac, &c., and 
by Hope, Williams, Carlisle, Pennock, and Moore, and other 
living authorities. 
2. With respect to the share in the circulation due to the 
auricular systole, it has been held to be active and of much 
importance, by Hervey, Senac, and others; while several living 
writers of great weight, adhering apparently to the views of 
Galen, Vesalius, &c., seem disposed to refuse to the auricles 
any very influential or positively important share in the cardiac 
operations; for examples I may cite Dr. Elliotson, Prof. 
Bouillaud, Dr. Hope, Sir B. C. Brodie, &c. 
3. With respect to the shape and dimensions of the ven- 
tricles in systole, it was held by Galen, Vesalius, Harvey, 
&c., that the heart is shortened in diastole and lengthened in 
systole; but the observations of Steno, Lower, Lancisi, Haller, 
and others, gave currency to opposite views; of late, however, 
the ancient opinion has been revived, for example, by Prof. 
Burdach and Prof. Bouillaud, as I understand their observa- 
tions, and by Drs. Pennock and Moore, the latest experi- 
mentalists on the subject that I know of, except my friends 
and myself. 
4. With respect to the precordial impulse, the great ma- 
jority of physiologists, adhering unqualifiedly to the ancient 
Opinion advocated by Hippocrates and Galen amongst the 
Greeks, and by Vesalius, Harvey, Lancisi, Senac, Haller, 
Hunter, and almost all modern writers, ascribe the cardiac 
pulsation to a blow or stroke (in the popular meaning of those 
words) given by the heart’s apex in systole to the ribs; while, 
in opposition to this view, may be cited the experiments of 
several recent observers, and the arguments of Mr. Carlisle, of 
hg er in his last edition, of Mr. Bryan*, Dr. Billing, 
c. &e. 
5. With respect to the diastole of the heart, it was held by 
* Lancet, v. 29. 
