274 
DR. PHILIP’S OBSERVATIONS ON 
those whose power of volition is impaired by disease. He will find the patient 
hesitate which leg to move at every step, and at length his attempts to move 
the limbs produce a confused and irregular action incapable of carrying him 
forward. 
The act of expanding the chest is an act of volition, it is an act in ordi- 
nary breathing rendered extremely easy by the gentleness of the motion re- 
quired, and the continual habit which renders it familiar, and is excited by a 
sensation proportionably slight, but which is as essential to it as stronger sen- 
sations are to more powerful acts of volition. Thus it is that on the removal 
of the sensorial power respiration ceases. It may be here said perhaps, that we 
have no instance of a muscle of voluntary motion continuing to act at short 
intervals during life ; but besides that this is begging the question, it is to be 
recollected that the action of the muscles in ordinary respiration is very slight, 
and performed at considerable intervals, for it is only during inspiration that 
the muscles act. They are quiescent during expiration, which in our usual 
breathing is performed by the elasticity of the cartilages and the weight of the 
parts concerned. There is perhaps no muscle of the body which could not 
without fatigue maintain a similar action were there a cause capable of exciting 
it. In certain diseases we find both more powerful and more frequent actions 
of the muscles of volition continued for years during the whole of our waking 
hours without any complaint of fatigue. 
When the change in the blood, effected by respiration, no longer takes place, 
most of the pulmonary vessels lose their proper stimulus, red blood ; and feel 
more directly perhaps the debilitating influence of black blood ; their functions 
therefore begin to fail. In proportion as this happens, the blood accumulates 
in the lungs. The right side of the heart consequently experiences an increased 
difficulty in emptying itself, and the due supply of blood to the left side fails. 
By the operation of these causes both sides of the heart, particularly in warm- 
blooded animals, soon lose their power after respiration ceases. The arteries 
under such circumstances, it is evident, cannot long supply fluids proper for 
the purposes of assimilation. The nervous and muscular solids therefore deviate 
from the state necessary for the functions of life, which at length cease in every 
part. 
The foregoing appears to be the order in which the functions always, with 
