OP HEALTH AND HUMAN NATURE. 45 



and influencing the most distant parts. The phenomena of the 

 mind have been metaphysically considered in the fifth section ; 

 they will be examined as functions of the nervous system in the 

 twelfth. 



The organic functions depend on fife in the proper accepta- 

 tion of the word. The word fife should be regarded, like the 

 word attraction or repulsion, as merely an expression of a fact. 

 In this point of view it may be as easily defined as any other 

 expression. By life we generally mean the power of organised 

 matter to preserve its particles in such chemical relations as to 

 prevent other chemical relations from inducing disorganisation, 

 or even to increase or decrease by internal appropriation and 

 separation ; to preserve in some measure a temperature distinct 

 from that of the surrounding medium ; to move certain parts of 

 itself sensibly (as muscles) or insensibly (as the capillaries) inde- 

 pendently of mere impulse, attraction, or repulsion i or if not 

 organised (as the fluids which form the embryo, the blood,) 

 the power of matter produced by an organised body endowed 

 with the properties above mentioned, to resist the ordinary che- 

 mical influences, and directly form (as the genital fluids) an 

 organised system so endowed, or directly contribute (as the 

 blood) to the organised substance of an already formed system 

 so endowed. 



That fluids are as susceptible of life as solids I cannot doubt. 

 There is no reason why they should not be so, although a person 

 who has not thought upon the subject may be as unable to con- 

 ceive the circumstance as a West Indian to conceive that water 

 may by cold become solid. It is impossible to deny that the male 

 and female genital fluids are alive, because from their union a liv- 

 ing being is produced that partakes of the vital qualities of each 

 parent. Accordingly Blumenbach, in his Commentatio de vitali 

 sanguinis, * grants both male and female genital fluids to be alive, 



'« ■ ' ' ■ " * ' ' i i . . i i 



* " In univcrsum sane post omnia quae super hoc argtnnento sive incditando 

 sive experiundo hactenu* elioere licuit, nulli humorum nostri corporis genuina 



