LIFE. 27 



We thus find in every living system a class of functions, not in 

 themselves dependent upon mind, as perfect in the vegetable 

 as in the animal, and pervading every part of the system. In 

 animals there further exist certain parts which, when endowed 

 with the common life of other parts, with the organic pro- 

 perties, are able to perform peculiar functions which give us the 

 notion of mind: the organ of these functions is termed brain, and, 

 by means of nerves and medullary prolongations, it maintains a 

 correspondence with the whole machine, influenced by and in- 

 fluencing the most distant parts. 



The ORGANIC FUNCTIONS depend on LIFE, in the proper accept- 

 ation of the word. The word life 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 pre- 

 serve 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 11 ; 

 to produce peculiar matters for its own purposes ; 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) independently of mere impulse, 

 attraction, or repulsion : or if not organised (as the fluid which 

 becomes the embryo, the blood,) the power of matter produced by 

 an organised body endowed with the properties above mentioned, 

 to resist the ordinary chemical influences, and even directly form 

 (as the embryotic fluid) an organised system so endowed, or 

 directly become, (as the fibrin, when it is secreted from the blood or 

 blood is effused, becoming vascular, and its new vessels inosculat- 



h So striking is this, that Stahl and his followers referred their notion of life 

 to this antiseptic property, and while he said, " Life is formally nothing more than 

 the preservation of the body in mixture, corruptible, indeed, but without the 

 occurrence of corruption," Junker said, " What we call life is the opposite of 

 putridity." 



Chemical affinities are not destroyed by life, but only so brought to play that 

 decomposition is not their result. Without the operation of chemical affinities 

 the composition of the body could not exist, nor many of its functions, as respir- 

 ation, secretion, &c., take place. The physical properties of matter are equally 

 indispensable. Cohesion, gravity, hardness, softness, and fluidity are essential, in 

 different parts ; elasticity performs an important part in many functions, as in 

 respiration and the rise of the epiglottis ; the laws of light and sound are indis- 

 pensable to the functions of the eye and ear. 



