70 



FUNCTIONS OF MAN. 



two series of actions, antagonistic to each other ; the one proceeding 

 from without and terminating in the brain, or passing from circum- 

 ference to centre, and comprising the external senses; the other, com- 

 mencing in the brain, and acting on external bodies, or proceeding 

 from centre to circumference, and including the internal senses, loco- 

 motion, and voice. The brain, in which one series of actions terminates 

 and the other begins, he considered the centre of animal life. In 

 organic life, he likewise recognized two series of actions : the one, pro- 

 ceeding from without to within, and effecting composition ; the other 

 passing from within to without, and effecting decomposition. In the 

 former, he included digestion ; absorption ; respiration, by which the 

 blood is formed ; circulation, by which the blood is conveyed to different 

 parts ; and the functions of nutrition, and calorification. In the latter, 

 that absorption by which parts are taken up from the body ; the cir- 

 culation, which conducts those parts or materials to the secretory or 

 depuratory organs ; and the secretions, which separate them from the 

 economy. In this kind of life, the circulation is common to the two 

 movements of composition and decomposition; and, as the heart is the 

 great organ of the circulation, he considered it the centre of organic 

 life. Lastly, as the lungs are united with animal life in the reception 

 of air, and with organic life as the organs of sanguification, Bichat 

 regarded them as the bond of union between the two lives. Genera- 

 tion constituted the life of the species. 



The classification, adopted in this work, is essentially that embraced 

 by M. Magendie ;* and, after him, by M. Adelon, 2 who has written one 

 of the best systems of human physiology that we possess. The FIRST 

 CLASS, or functions of relation or animal functions, includes those that 

 establish our connexion with the bodies that surround us ; the sensations, 

 voluntary motions, and expressions. The SECOND CLASS, or functions 

 of nutrition, comprises digestion, absorption, respiration, circulation, 

 nutrition, calorification, and secretion ; and the THIRD CLASS, the func- 

 tions of reproduction, generation. 



TABLE OF FUNCTIONS. 



I. Functions that relate to 

 the preservation of the indi- 

 vidual. 



I. Animal or of Relation. 



II. Nutritive. 



III. Reproductive. 



1 . Sensation. 



2. Muscular Motion. 



3. Expression or Language. 



4. Digestion. 



5. Absorption. 



6. Respiration. 



7. Circulation. 



8. Nutrition. 



9. Calorification. 

 ^ 10. Secretion. 



II. Functions that relate to 

 the preservation of the species. 



In studying each of these functions, we shall first of all describe the 

 organ or apparatus concerned in its production, but so far only as is 

 necessary in a physiological point of view; and shall next detail what 

 has been called the mechanism of the function, or the mode in which 

 it is effected. In many cases, it will happen, that some external agent 



11. Generation. 



1 Precis, &c., i. 32. 



9 Physiologie de 1'Homme, 2de edit., i. 116. Paris, 1829. 



