CO ON THE STUDY OF PHYSIOLOGY. 



he possesses, but by the sincere and honest pains he has 

 taken to discover truth. This it is that invigorates his 

 mind, and, by exercising the mental springs, preserves 

 them in full activity. Possession makes us quiet, indolent, 

 proud. If the Deity held in his right hand all truth — and 

 in his left, only the ever-active impulse, the fond desire, 

 and longing after truth, coupled with the condition of con- 

 stantly erring — and should offer me the choice ; I should 

 humbly turn towards the left, and say, ' Father, give me 

 this ; pure truth is fit for thee alone "*.' " Thus spoke a 

 sage ; and his determination seems as wise as the famous 

 choice of Hercules. 



In commencing the study of physiology, we are first led 

 to inquire, whether living beings are subject to the same 

 laws as inorganic bodies ; whether the vital processes can 

 be explained on the same principles as the other phenomena 

 of matter; whether, in short, the elucidations of the physi- 

 cal sciences are equally applicable to the science of life. 

 That animals obey those general laws which regulate mat- 

 ter and motion in all other cases ; that all their parts, as 

 well as their entire masses, are subject to the influences of 

 gravity. Impulse, and the like ; is too obvious to be a 

 subject of question. The point of inquiry is, whether the 

 internal movements of the animal machine are explicable 

 by the laws of mechanics and hydraulics; whether, like 

 these, they can be subjected to calculation ; whether the 

 changes of composition. Incessantly going on in all parts of 

 the frame, can be assimilated to the operations of our labo- 

 ratories, or reduced to the laws of external chemistry ; 

 whether any living phenomena can be so far likened to 

 those of electricity, galvanism, magnetism, as to justify us 

 in referring for their explanation to the same principles. 



In the beginning of the last century, the leading autho- 

 rities in physiology, of whom Boerhaave may be men- 

 tioned as the head, supposed that all the functions of the 

 living body, except the will, are carried on by mechanical 



* Trewrasv^. Biologic ; b. 



