188 THOUGHTS ON THE PHYSIOLOGY OF THE HEART. 
formed of solid or fluid, so that substance in some shape be 
there. The walls of venticles and the fleshy pillars contract 
and propel a sufficiency of blood into the arteries to support 
life, almost the same amount as if the auricle were con- 
tracted. 
Then, in instances where the ventricle is ossified, such 
ossification usually involves the pericardium rather than the 
walls of the heart. It may cripple the substance of the 
ventricle, but it cannot affect the fleshy pillars. Those and 
the auricle are left entire, and in a normal condition, although 
the movements of the ventricle generally are interfered with. 
Well, the blood flows in; the extra energy of the veins upon 
the dilatation of the auricles filling both cavities. The auricle 
contracts. It does not matter whether the valve be at the 
mouth of a vessel or a mile distant ; its action is the same. 
No blood being able to pass into the contracting cavas, a 
portion is necessarily sent up the artery by this movement. 
The remainder is supplied by the contraction of the fleshy 
pillars pulling down the auriculo-ventricular valves. 
I confess that there would then be an irregularity of the 
pulse. But the object I aim at is to show how the supply 
of blood could by any means be accomplished ; which, by the 
received theory of the circulation, would be an impossibility. 
Among the proofs which I regard as confirmatory of the 
views herein advanced, is the venous pulse, or the pulsation 
to be observed in the jugulars of certain horses. This pulse 
I look upon as caused by the contraction of the cavas, when 
all the blood contained within those veins of course cannot 
be urged in one direction. A portion of it is by the impetus 
sent up the vein, and this portion dilating the vein and 
making its presence known by, for a time, opposing the 
current, gives rise to the venous pulse. Of course the 
impetus, coming from an opposite direction, is more felt, 
because the current has hardly ceased running with greater 
speed towards the heart. Any check in its progress acts like 
a sudden stop put to a line of carriages when moving in 
single file. The pull-up is felt even by the most distant of 
the line ; and, as we know, waves of motion are more easily 
conveyed through fluids than through solids, it can be nothing 
strange if a suddenly contrary impulse springing from a 
vessel in direct communication with the heart, is perceptible 
in such a vessel as the jugular, even granting the muscular 
coating of veins not to be continuous. 
