446 HISTORY OF PHYSIOLOGY. 



on this account, to despair. The very instance to 

 which I am referring shows us how rich is the pro- 

 mise of the future. Why, says Cuvier 19 , may not 

 natural history one day have its Newton ? The idea 

 of the vital forces may gradually become so clear 

 and definite as to be available in science ; and 

 future generations may include, in their physiology, 

 propositions elevated as far above the circulation of 

 the blood, as the doctrine of universal gravitation 

 goes beyond the explanation of the heavenly motions 

 by epicycles. 



If, by what has been said, I have exemplified 

 sufficiently the nature of those steps in physiology, 

 which, like the discovery of the circulation, give an 

 explanation of the process of some of the animal 

 functions, it is not necessary for me to dwell longer 

 on the subject; for to write a history, or even a 

 sketch of the history of physiology, would suit 

 neither my powers nor my purpose. Some further 

 analysis of the general views which have been pro- 

 mulgated by the most eminent physiologists, may 

 perhaps be attempted in treating of the Philosophy 

 of Inductive Science; but the estimation of the 

 value of recent speculations and investigations must 

 be left to those who have made this vast subject 

 the study of their lives. A few brief notices may, 

 however, be here introduced. 



19 Ossem. Foss. Introd. 



