\ D MAN. 



u'ri transcendent math.-: ..-nius raised it t.. 



vel of a demonstration. 'I kioni, 



bed upon tin- induction.- of Newton 



'light* were rooted 



in their thoughts, ami a just distribution of merit would 

 assign to them ;i fair portion of tin- f disc\- 



Mtitir theories sometimes float like rumors in the 

 air before th . complete expression. The doom 



of a doctrine is often practically sealed, and the tnuli of 



often practi.-ally accepted, loii.u' prior I 

 stration of eit i ror or the truth. Perpetual n. 



was discarded before it was pm\i-il h !> nj.j,. 

 law; and, a.s regards the connection and interact;' 

 natural forces, intimations of m- lies are strewn 



through the writings of Leibnitz, I'.ovU-. Ilooke, Locke 

 and others. 



lining ourselves to recent times, Dr. Ingleby has 

 |x>inted out to me some singularly sagacious remarks bear- 

 ing upon this question, which were published by an 

 anonymous writer iu 1820. Roget's penetration was con - 



us in 18x >( .t. Molir had grasped in 1837 so: 

 lying truth. The writings of l-'aiaday furnish frequent 

 illustrations of l;is profound belief in the unity of nature. 

 " J have long," he writes in 1845, " held an opinion I 

 amounting to conviction, in common, 1 believe, with other 

 lovers of natural knowledge, that the various forms under 

 which the forces of matter arc made manifest have one 

 common origin, or, in other words, are so directly i 

 and niiitu; mlent, that they are convertible, as it 



one into another, and possess equivalence of ; 

 in their action." Hi- <>wn researches on ma^ 



..on electro-chemistry, and on the "magnetization 

 led him directly to this belief. At an early date 



ado his mark upon this <ju. 



Colding, though starting from a nu -taphv.-'u -al basis, grasped 

 eventually the relation between heat and n 

 work, and sought to determine it expei irm -ntally. 

 here let me say, that to him who ha.- ith at 



. and who in his dealings with scientific hi.-: 

 his soul unua al or 



.'Cession to hi.-tol ie k : 



niei ,f pr,,v,-,i me: it , in-. re 



.ally if that :i 



