TO PHYSIOLOGY AND PATHOLOGY. 35 



circulation and respiration, and the changed phenomena of heat, which characterize 

 the febrile condition, as well as the relation of their mutual dependence. 



If we exclude from investigation, as inexplicable phenomena, the subjective 

 indications, the feelings of indisposition, and of heat and cold, it still remains to 

 trace the connection existing between the alteration of the spinal cord, the 

 accelerated movements of the blood and the respiratory apparatus, and the altered 

 phenomena of heat. Before we can obtain any explanation of this, we must 

 arrive at a conception of motion, and seek the source of a moving force and heat 

 in the animal body. If we could trace the cause of fever according to the physical 

 method, and consider that by the co-operation of many, or let us say of two 

 causes, a certain amount of force is engendered in the heart itself, by which the 

 circulation of the blood is affected ; then the motion will be regular or normal, if 

 the number of the beats of the heart be equal in every minute, and when the 

 force is thus divided over equal periods. 



POINT OF VIEW OF THE INVESTIGATION. 



If this same amount of force, in consequence of the disturbed relation of the 

 two causes, which have their seat in the heart, at one time increases and at another 

 diminishes, the pulsations of the heart will be at one time quicker, and at another 

 slower. The force engendered is in this case not proportionate to the term of its 

 consumption. It is clear that, on the supposition of this force being engendered in 

 the heart, the alteration in the spinal cord can exercise no other influence upon the 

 change in the phenomena of motion, or upon the accelerating or retarding of the 

 heart's action, than that, in consequence of its condition, it may oppose, in some 

 manner or other a smaller resistance to motion at one period than at another. The 

 causes of the effects of motion do not exist in the heart alone ; they are distributed 

 in every part of the organism, in the spinal cord, as well as in every individual 

 muscular fibre. 



INQUIRY INTO THE CONNECTION OF THE SPINAL CORD WITH 

 THE EFFECTS OF MOTION. 



We may conjecture that the movement of the heart, as well as that of all other 

 parts of the organism, the motion of the intestines, and the voluntary motions, 

 proceed from the spinal cord, and it is evident that a change in the condition or 

 character of this organ must be followed by a change in all the phenomena of 

 motion. The same must happen when any part of the nerves, standing in 

 connection with the spinal cord, and with the circulatory apparatus, &c., suffers a 

 change of condition or properties, and this changed activity must exercise a retro- 

 grade influence upon the spinal cord and the apparatus of motion. The laws of 

 the propagation or communication of motion, are every where the same, whatever 

 causes may have called them forth. 



The cause of motion in a mill, the rotatory motion of the stone, the bolting 

 of the flour, &c., are not occasioned by the wheel, for that is a portion of 

 the mill itself. It is quite certain that an irregularity in the working of the 

 mill may be occasioned by the removal of a few of the wings of the wheel, 

 by which the pressure of the water on these parts ceases ; it may also, however, 

 be occasioned by the breaking off of the cogs of one of the other wheels of the 

 mill, when an irregularity of motion will be perceived not only in this wheel, but 

 in every other part of the wheel. 



