600 



In 1826 he obtained a long leave of absence in order to proceed 

 to Berlin to perfect and publish his new theory, which appeared in 

 1827 under the title "The Galvanic Circuit mathematically treated, 

 by Dr. G. S. Ohm." When this work first appeared, it had not the 

 fortune to attract notice from the leading scientific men of the day, 

 nor did it gain for its author consideration or favour from the au- 

 rities then at the head of the affairs of education and learning in 

 Prussia, by whom, indeed, he was received in a manner which 

 showed an entire misapprehension of his scientific activity and of his 

 great merits. His susceptibilities thus wounded, he did not delay a 

 moment to declare that, after such a reception, it was impossible for 

 him to retain the appointment he held at Cologne. With the deepest 

 feelings of mortification and grief, he left the place, thrown back 

 into private life with most precarious means of existence, and de- 

 prived of all the requisite resources for pursuing his investigations. 

 Seven of the best years of his life were in this way lost to science ; 

 but from these adverse circumstances he was at last withdrawn in 

 1833, when the Bavarian government appointed him Professor in the 

 Polytechnic School at Nuremberg. 



Whilst Ohm was usefully employed in this new sphere, his theory 

 of the voltaic circuit began to be appreciated both at home and 

 abroad, and in 1841 the Royal Society of London awarded to him 

 the Copley Medal, the highest honour in its power to bestow ; and 

 to mark still more its high estimation of the eminent services he 

 had rendered to science, he was elected, in 1842, a Foreign Member 

 of the Society. This judgment, it is acknowledged by his country- 

 men, had the effect of entirely removing the obstacles which had 

 hitherto impeded his way ; the conclusions of his theory became 

 known as " Ohm's laws " in all elementary works on physics, and 

 throughout Europe his position was recognized as among the most 

 eminent philosophers of Germany. 



Amidst his active duties as Rector of the Polytechnic School at 

 Nuremberg, and Professor of Physics, he found time to make 

 advances in the scientific career which his theory of the voltaic 

 circuit had opened to him. Physicists have long been convinced 

 that the various forces to which we ascribe the phenomena of Light, 

 Heat, Electricity and Magnetism, must all have a common origin ; 

 transformations of one series of phenomena to another have even been 



