32 THE BIOLOGICAL PROBLEM 



of equations, and return to the chemical bases of vital functions. 

 We shall see that other difficulties await us. 



The analysis of elements constituting living matter or 

 elaborated by it, rapidly demonstrated that it was composed 

 of elementary substances in no way different from those found 

 everywhere in nature. The carbon of coal and diamond, the 

 potassium, sodium, and calcium of inorganic salts, the nitrogen 

 and oxygen of air are identical with those of our tissues or of 

 our blood. There was therefore, in principle, no reason why 

 the classical methods of chemistry should not be applicable to 

 the basic substances of organized matter. In analysing these 

 compounds the conviction was rapidly obtained that a great 

 number of simple elements entered into their constitution. 

 In the same way any machine or any work of art can be reduced 

 under the mortar to a given quantity of chemical bodies and 

 definite elements. But a machine, a work of art, a Living 

 organism, only exist as such by reason of an organization at 

 a scale superior to that of molecular magnitude. At this scale, 

 the properties of the constituent molecules seem to efface 

 themselves in order to allow the birth of new properties due 

 to their conjunction in space and in time, in definite propor- 

 tions, following an order, a plan which establishes a bond 

 between them, and which creates their reason of existence and 

 their harmony.^ This brings us back to Hopkins' observation, 

 quoted on page 25. 



In brief, our body is made up of cells, the cells of molecules, 

 and the molecules of atoms. But these atoms are not all the 

 reality of the human body. The way in which the atoms, the 

 molecules, and the cells are arranged, and which results in 

 the unity of the individual, is also a reality, and how much 

 more interesting. The molecules of any substance can always 

 be decomposed into their atomic elements, and these in turn 

 into their sub-atomic elements, the electrons and the protons. 

 But this dissociation results in the disappearance of the 

 properties which gave this molecule its chemical individuality 



^ In connexion with harmony in science, the first pages of Henri 

 Poincare's admirable book. Science et Methode, should be read. 



