THE 



PHYSIOLOGICAL ANATOMY 



AND 



PHYSIOLOGY OF MAN. 



INTRODUCTION. 



THE aim of all natural knowledge is to ascertain the laws which 

 control and regulate the phenomena of the universe. So nume- 

 rous, and so diversified are these phenomena, that a division of 

 labour has been found, not merely convenient, but absolutely neces- 

 sary, for the study of them. The position and movements of the 

 planetary system, the crust of the earth, and its various com- 

 ponent strata, the treasures hidden in its womb, the abundant 

 vegetation that grows upon its surface, or beneath its waters, and 

 the numberless hosts of animals that dwell upon the land, or in the 

 rivers, lakes, and seas, form separate branches of scientific investi- 

 gation, between which a sufficiently distinct line of demarcation 

 is established by the nature of the objects of inquiry peculiar to 

 each. But, in all departments of science, the same general rules, 

 for conducting the investigation, prevail, and it is only by a close 

 adherence to these, that we can arrive at safe and satisfactory 

 conclusions. 



In any scientific inquiry, the first step must be, to form a 

 general notion of the characters and properties of the objects 

 of investigation. In the next place, it is necessary to observe 

 carefully the phenomena which they naturally present; and, if 

 they be within our reach, to produce such variation in them by 

 artificial means (by experiments), as may serve to throw light 

 upon them. If the phenomena, under observation, be complex, we 

 must analyse them, with a view to ascertain the simpler ones, 

 of which they are composed. By this analysis, and by the elimina- 

 tion of such as are merely collateral, we arrive at a phenomenon, 



VOL. I. B 



