170 REPORT—1840. 
Heart’s action much accelerated. 
July 4th. Animal pithed, and artificial breathing established. 
The experiments on the mitral valves then repeated. The left 
auricle was inverted by the finger and the valves impeded or 
kept asunder by the finger, in the auri-ventricular opening, when 
various murmurs accompanied or followed the first sound ; the 
second sound being simply either much weakened or sup- 
pressed ; and the normal sounds returned on the withdrawal 
of the finger. ‘This experiment was often repeated with similar 
results. 
A finger being placed on the exterior circumference of the 
mitral and aortic valves respectively at the same moment, simi- 
lar jerking motions perceived in each; at the closing of the 
valves and evolutions of the two cardiac sounds, the finger, 
when in the auri-ventricular opening, was sensible of something 
like flapping, pushing and tension, as it were, in and by the 
valves, and the supposed edge of the valve was felt tense in 
systole; and, if divided by the point of the finger, the edges of 
the opposite valves were thought to give a feeling of resistance 
such as valvular tension must cause, supposing such tension to 
occur. The first sound was protracted and dull, wanting the 
sharply defined beginning such as a flap would give when the 
valvular action was interrupted by the finger. The first sound 
was obscure, but audible on extraction of the heart, when the 
organ was irritated to contraction. 
OssERVATION VI. 
July 3rd.—Subject, a Turtle, weight 150 Ibs. No distinct 
pulsation could be heard externally. After decapitation and 
removal of the callipée the heart was felt by one of the Com- 
mittee, pulsating regularly, and two distinct sounds were 
heard (Wms.), with an interval between; the heart ceased 
beating too soon to allow of the other member of the Com- 
mittee (Cg.) making any satisfactory observation. 
OxsservaTion VII. 
Comparative Observation. 
The observations of the Committee on the motions and 
sounds of the Heart had been previously made almost ex- 
clusively on donkeys and dogs, animals whose cardiac struc- 
ture and modes of action are generally known to agree with 
those of the human subject. It was therefore thought very 
desirable to extend their observations more widely over the 
scale, as by such means it was thought some useful generaliza- 
tion might be obtained, and the views of the Committee be at 
