CHAPTER I 



INTRODUCTORY 



Of the chemistry of his day and generation, Kant declared 

 that it was "a science, but not science," — "eine Wissenschaft, 

 aber nicht Wissenschaft"; for that the criterion of physical 

 science lay in its relation to mathematics. And a hundred years 

 later Du Bois Reymond, profound student of the many sciences 

 on which physiology is based, recalled and reiterated the old 

 saying, declaring that chemistry would only reach the rank of 

 science, in the high and strict sense, when it should be found 

 possible to explain chemical reactions in the light of their causal 

 relation to the velocities, tensions and conditions of equihbrium 

 of the component molecules ; that, in short, the chemistry of the 

 future must deal with molecular mechanics, by the methods and 

 in the strict language of mathematics, as the astronomy of Newton 

 and Laplace dealt with the stars in their courses. We know how 

 great a step has been made towards this distant and once hopeless 

 goal, as Kant defined it, since van't Hoff laid the firm foundations 

 of a mathematical chemistry, and earned his proud epitaph, 

 Physicam chemiae adiunxit*. 



We need not wait for the full reahsation of Kant's desire, in 

 order to apply to the natural sciences the principle which he 

 urged. Though chemistry fall short of its ultimate goal in mathe- 

 matical mechanics, nevertheless physiology is vastly strengthened 

 and enlarged by making use of the chemistry, as of the physics, 

 of the age. Little by little it draws nearer to our conception of 

 a true science, with each branch of physical science which it 



* These sayings of Kant and of Du Bois, and others like to them, have been 

 the text of many discourses : see, for instance, Stallo's Concepts, p. 21, 1882 ; Hober, 

 Biol Cetdmlbl. xix, p. 284, 1890, etc. Cf. also Jellett, Rep. Brit. Ass. 1874, p. 1. 



T. n. 1 



