VI PREFACE. 



Various repetitions occur in the course of the 

 work, which to some may seem unnecessary, and 

 for which I ought to solicit the indulgence of the 

 reader. These have arisen chiefly from the inti- 

 mate manner in which the different functions are 

 connected with each other, rendering it impossible 

 to explain one without constantly referring to the 

 rest. Occasionally, also, the novelty and import- 

 ance of the subject have led me to risk repetition, 

 in order to ensure attention , but I trust that these 

 faults, if felt as such, will be forgiven. 



Those who desire to obtain further information 

 of a popular nature in regard to the structure of 

 man, will find an excellent treatise on Animal 

 Physiology, in four of the earlier numbers of the 

 Library of Useful Knowledge. It is understood 

 to be from the pen of an able physician in London, 

 with whose sentiments on the subject now before us, 

 as expressed in the following extract from his con- 

 cluding page, I need hardly say I entirely concur : > 



" The obvious and peculiar advantages of this 

 kind of knowledge are, that it would enable its 

 possessor to take a more rational care of his health ; 

 to perceive why certain circumstances are bene- 

 ficial or injurious ; to understand, in some degree, 

 the nature of disease, and the operation as well of 

 the agents which produce it as of those which coun- 

 teract it ; to observe the first beginnings of deranged 

 function in his own person ; to give to his physician 

 a more intelligible account of his train of morbid 

 sensations as they arise ; and, above all, tc co- 

 operate with him in removing the morbid state on 



