THE BEGINNINGS OF LIFE. 299 



tionist's point of view, are supposed to take origin from 

 the recompositions occurring amongst colloidal mole- 

 cules. Colloids possess so strong an inherent tendency 

 to undergo change, that they were said by Professor 

 Graham to be endowed with properties which form 

 the basis of those manifested by living things. Matter 

 when it passes into the crystalline condition exhibits 

 properties of a certain kind ; and when it passes into 

 the living condition it exhibits properties of another 

 kind, to which we commonly apply the term c vital.' 

 Now the question in each case is, whether by mere 

 concurrence of certain physical conditions, aiding 

 and abetting the inherent properties of the matter 

 itself, some kinds of matter can fall into modes of 

 combination called crystalline, whilst other kinds are 

 capable of falling into modes of combination called 

 living $ or whether, in each case, a pre-existing c germ' 

 of the particular kind of matter is necessary, in order to 

 determine, in suitable media, either of these modes of 

 combination. Are we to believe that crystals can 

 appear in no solution whatsoever without the pre- 



I'activite* e'eteint a moment meme oil il se produit ; il ne conserve 

 ensuite sa forme comme le caillot, que par sa seule cohesion, par 1'en- 

 chainement chimique de ses elements, et il ne manifeste plus aucune 

 activite, tant que de nouvelles causes ne viennent point deranger 1'equi- 

 libre. Le corps organise au contraire, se maintient par une production 

 incessante, par la continuite des mouvements plastiques, par la perma- 

 nence de 1'antagonisme de forces qui lui a donne naissance. La per- 

 ennite ou la persistance de 1'activite nous apparait done comme 

 caractere de la vie." Trails de Physiologic, translated by Jourdan, 

 1839, t. iv. p. 129. 



