Michael Faraday, his Life and Works. 435 



path for himself. What is this path ? I shall be asked. This is 

 not easy to say ; but I will nevertheless attempt it. 



At the commencement of the present century, thanks to the 

 important works of which it had been the subject, the science of 

 physics had acquired a character of precision and clearness which 

 seemed almost to make of it a mathematical science. The fine 

 treatise, in four volumes, on Experimental and Mathematical 

 Physics, published in 1816 by M. Biot, gives the most correct 

 and complete idea of the point at which this science had arrived. 

 To the confusion which still reigned in the middle of the eigh- 

 teenth century between the various departments of the science, 

 to the ignorance which then still prevailed upon a great number 

 of these departments, succeeded a clear and substantial analysis 

 of all the phenomena, brought under simple and rigorous laws. 

 Heat, light, electricity, and magnetism were regarded in it as so 

 many distinct agents, having their special properties and obeying 

 their own laws. Calculation was admirably fitted to these clear 

 and precise conceptions j hence we find it greatly used, as witness 

 the very title of M. Biotas treatise. 



The great discovery of CErsted (in 1820), upon the relations 

 existing between electricity and magnetism, began to diminish 

 confidence in this mode of considering the phenomena, a confi- 

 dence which was already a good deal shaken by the researches 

 of Fresnel and Arago upon light. The breach once opened, the 

 fortress was soon entered; and among the most intrepid assail- 

 ants Faraday figures in the front rank. By his researches on the 

 condensation of gases, he shows that there is nothing absolute in 

 the laws of Mariotte and Gay-Lussac and in the distinction so 

 generally accepted between vapours and permanent gases. By 

 his investigations upon voltaic electricity, he establishes between 

 chemical affinity and the production of electricity a relation so 

 intimate that it seems as if the one was only a form of the other. 

 By his discovery of induction, he brings in mechanical movement 

 as an important element in the production of electrical pheno- 

 mena. By his experiments on the influence of the magnet and 

 of electricity on polarized light, and by those which were the 

 consequence of it, he opens to science a new path which no one 

 had foreseen. He succeeds thus in establishing between the na- 

 tural agents which we name light, heat, electricity, magnetism, 

 chemical effinity, and molecular attraction, such intimate rela- 

 tions, such a connexion, that it is impossible not to think that we 

 shall one day succeed in demonstrating that they are only differ- 

 ent forms of the same agent. No doubt he is not the only one 

 that has followed this path. Many others have brought in their 

 contingent to this work of demolition and reconstruction ; but he 

 was one of the first, most active, and most persevering. There- 



