LIFE AND LETTERS OF FA HAD A T. 313 



in our day. They arise from an imperfect acquaintance with 

 the nature, present condition, and prospective vastness of 

 the field of physical inquiry. The tendency of natural 

 science doubtless is to bring all physical phenomena under 

 the dominion of mechanical laws; to give them, in other 

 words, mathematical expression. But our approach to 

 this result is asymptotic; and for ages to come possibly 

 for all the ages of the human race Nature will find room 

 for both the philosophical experimenter and the mathe- 

 matician. Faraday entered his protest against the fore- 

 going statement by labeling his investigations " Experi- 

 mental Researches in Electricity." They were completed 

 in 1854, and three volumes of them have been published. 

 For the sake of reference, he numbered every paragraph, 

 the last number being 3,362. In 1859 he collected and 

 published a fourth volume of papers, under the title, 

 "Experimental Researches in Chemistry and Physics." 

 Thus did this apostle of experiment illustrate its power, 

 and magnify his office. 



The second volume of the Researches embraces memoirs 

 on the Electricity of the Gymnotus; on the Source of 

 Power in the Voltaic Pile; on the Electricity evolved by the 

 Friction of Water and Steam, in which the phenomena and 

 principles of Sir William Armstrong's Hydro-electric ma- 

 chine are described and developed; a paper on Magnetic Rota- 

 tions, and Faraday's letters in relation to the controversy 

 it aroused. The contribution of most permanent value 

 here, is that on the Source of Power in the Voltaic Pile. 

 By it the Contact Theory, pure and simple, was totally 

 overthrown, and the necessity of chemical action to the 

 maintenance of the current demonstrated. 



The third volume of the Researches opens with a memoir 

 entitled "The Magnetization of Light," and the "Illu- 

 mination of Magnetic Lines of Force." It is difficult even 

 now to affix a definite meaning to this title; but the dis- 

 covery of the rotation of the plane of polarization, which it 

 announced, seems pregnant with great results. The writ- 

 ings of William Thomson on the theoretic aspects of the 

 discovery; the excellent electro-dynamic measurements of 

 Wilhelm Weber, which are models of experimental com- 

 pleteness and skill; Weber's labors in conjunction with his 

 lamented friend Kohlrausch above all, the researches of 

 Clerk Maxwell on the Electro-magnetic Theory of Light 



