USEFULNESS OF PHYSIOLOGICAL KNOWLEDGE. 17 



are great marks of distinction, and, considered in a 

 general point of view, amply suffice to divide the 

 two great classes of animated beings; and while 

 some animals exhibit individual powers in greater 

 perfection, man stands far their superior, not only 

 In combining in his own body all the senses and 

 faculties possessed among them, but in being en- 

 dowed with moral and intellectual powers which 

 are denied to them, and which place him at once at 

 the head of the living creation, and constitute him 

 a moral, religious, intelligent, and responsible being. 



So numerous and important are the various organs 

 of which the human frame is composed, and so 

 closely are they linked with each other in their 

 action, that, in treating of them, it is difficult, or 

 rather impossible, to follow any arrangement which 

 shall not involve considerable repetition. On the 

 present occasion, however, a systematic mode of 

 proceeding is not essential, my object being merely 

 to communicate a general knowledge of a few of 

 the more important functions, partly with a view to 

 the direct practical purposes to which such informa- 

 tion may be applied, and partly for the sake of rous- 

 ing, public attention to the necessity of including 

 this branch of science in every plan of what is 

 called a liberal education. 



Let it not be said that knowledge of this descrip- 

 tion is superfluous to the unprofessional reader ; for 

 society groans under the load of suffering inflicted 

 by causes susceptible of removal, but left in opera- 

 tion in consequence of our unacquaintance with our 

 own structure, and of the relations of the different 

 parts of the system to each other and to external 

 objects. Every medical man must have felt and 

 lamented the ignorance so generally prevalent in 

 regard to the simplest functions of the animal sys- 

 tem, and the consequent absence of judicious co- 

 operation of friends in the care and cure of the 

 sick. From unacquaintance with the commonest 

 B2 



