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 Wissen- 

 schaft — for that the criterion of true science lay in its relation to 

 mathematics*. This was an old story : for Roger Bacon had called 

 mathematics porta et clavis scientiarum, and Leonardo da Vinci had 

 said much the samef. Once again, a hundred years after Kant, 

 Du Bois Reymond, profound student of the many sciences on which 

 physiology is based, recalled the old saying, and declared that 

 chemistry would only reach the rank of science, in the high and 

 strict sense, when it should be found possible to explain che^dcal 

 reactions in the light of their causal relations to the velocities, 

 tensions and conditions of equihbrium of the constituent 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 Newtoii and Laplace dealt with the stars in 

 their courses. We know how great a step was made towards this 

 distant goal as Kant defined it, when van't Hoif laid the firm 

 foundations of a mathematical chemistry, and earned his proud 

 epitaph — Physicam chemiae adiunxitX- 



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

 to the natural sciences the principle which he laid down. Though 

 chemistry fall short of its ultimate goal in mathematical mechanics §, 

 nevertheless physiology is vastly strengthened and enlarged by 



* " Ich behaupte nur dass in jeder besonderen Naturlehre nur so viel eigentliche 

 Wissenschaft angetroffen konne als darin Mathematik anzutreffen ist" : Gesammelte 

 Schriften, iv, p. 470. 



t "Nessuna humana investigazione si puo dimandare vera scienzia s'essa non 

 passa per le matematiche dimostrazione." 



X Cf. also Crum Brown, On an application of Mathematics to Chemistry, Trans. 

 R.S.E. XXIV, pp. 691-700, 1867. 



§ Ultimate, for, as Francis Bacon tells us: Mathesis philosophiam naturalem 

 terminare debet, non generare aut procreare. 



