MOJYERA, AND THE PROBLEM OF LIFE. 565 



order to understand motility ; that is, to understand it in the same 

 manner as we understand other natural processes not belonging to vi- 

 tality. We have here evidently only a display of specific chemistry. 

 But, then, chemistry is specific all through down to H 2 0, C0 2 , and NH 3 , 

 and who knows how much further ? 



Expansion and contraction are, as is well known, no uncommon 

 physical concomitants of mere chemical activity, even without addition 

 or subtraction of masses ; and it is of fundamental importance clearly 

 to comprehend that vital expansion and contraction are of the same 

 chemical kind, being due to the intrinsic nature of the compound, not 

 to the mere addition or subtraction of mass. 



A part of the protoplasm of a moner expands. Chemical compo- 

 sition of a specific kind has taken place, and now it is the physical 

 property of this peculiar compound to occupy more space than before ; 

 then the same part of the moner contracts in consequence of chemical 

 decomposition. It is the physical property of the less complicated 

 organic molecule to occupy so much less space. The mass of the added 

 or separated material fills but a very small part of the entire space of 

 expansion or contraction. The expansion as well as the contraction 

 forms part of the specific nature of those different kinds of protoplasm. 

 The organic substance of the moner, plus the separating molecule, is 

 the expanded material. The organic substance of the moner, minus 

 the separating molecule, is the contracted material. The activities of 

 expansion and contraction are merely the physical expression of the 

 gradual process of composition or decomposition occurring within the 

 living substance ; they are marks of the shifting of the special relation 

 existing between the protoplasm and its medium during the transi- 

 tional stages from one state of equilibrium to another. 



The great truth which I wish to make quite evident is, that the 

 specific nature of the acting substance constitutes the real power in 

 motility, and not, as is usually believed, the addition of something 

 from outside. 



Vital processes will never become intelligible until it is clearly per- 

 ceived that all vital efficacy resides in the living substance itself, forms 

 an integral part of its specific nature. Many serious misconceptions 

 are afloat with regard to the source of vital power. Science has as 

 yet scarcely penetrated into the outermost precincts of the laboratory 

 of life. The so-called vital dynamics of the present day are beggarly 

 conceptions when measured against the actual wealth of vital mani- 

 festations. All we know is, that if so much pressure, so much heat, 

 etc., will effect a new molecular equilibrium in a certain substance, 

 that substance will return to the medium what it has received from it 

 in reassuming its former state. 



Will any one pretend to compute the value of the influences which 

 the living substance in the course of ages has absorbed from its me- 

 dium, in order to become what it at present is ? Yet it is these assimi- 



