CRITICISMS AND DIFFICULTIES 33 



endowed with definite characteristics.^ The characteristics of 

 the individual at a different scale always superimpose them- 

 selves on the characteristics of the materials. 



'Would a naturalist who had only studied an elephant 

 through the microscope believe that he had a thorough 

 knowledge of this animal?' asks Henri Poincare. 



Thus, on the one hand, we are necessarily led to the physical 

 and chemical study of living matter, for without this analysis 

 the mechanism of the physiological functions would remain 

 a mystery. On the other hand, we must always consider at 

 the same time the organism as a whole, without ever losing 

 sight of the special conditions of all separate phenomena which 

 constitute the individual. There is, therefore, a kind of 

 antinomy between the aims and methods of the medical man 

 and those of the bio-chemist or bio-physicist. This antinomy 

 is only apparent, but it suffices to account for the difficulty 

 experienced in establishing an intimate collaboration between 

 these two disciplines. 



In reality, the chemist and physicist seek the elementary 

 phenomenon by cutting up bodies fictitiously into infinitely 

 small cubes, because the conditions of the problem which 

 undergo slow and continuous variations when one passes from 

 one point of the body to another, can be considered as constant 

 in the interior of each one of these small cubes. Their 

 ambition is to establish the law of certain variations. This 

 law has a meaning only on condition that sufficiently simple 



^ There is much to be said on this subject, and particularly on the 

 biological properties derived from the increase of the complexity and 

 of the molecular weight of the organic substances. Above a certain 

 molecular weight the definition of the chemical unit, the molecule, 

 does not suffice to characterize all the properties of the unit. Simi- 

 larly in the atoms, radioactivity accompanies the complication and 

 fragility resulting from the high atomic weight. Pigmentary proteins 

 have been found in certain animals (snails) of enormous molecular 

 weight (more than five millions). These immense molecules, if they 

 can still be given this name, are so complicated, that it is quite possible 

 that in these primitive organisms, they function as comiplete organs. 

 This observation seems to be confirmed by the fact that, in this 

 particular case (hemocyanine of Helix's blood) the molecular weight 

 varies according to the physiological activity. (Roche.) 



