336 



Awards of Medals. 

 The Council has awarded the Copley Medal for the present year 

 to Dr. G. S. Ohm, of Nuremberg, for his researches into the laws 

 of Electric Currents, contained in various memoirs published in 

 Schweigger's Journal Poggendorff's Annalen, and also in a sepa- 

 rate work, entitled Die Galvanische Kette Mathematisch Bear- 

 bitet, published at Berlin in the year 18^7. In these works, Dr. 

 Ohm has established, for the first time, the laws of the electric cir- 

 cuit ; a subject of vast importance, and hitherto involved in the 

 greatest uncertainty. He has shown that the usual vague distinc- 

 tions of intensity and quantity have no foundation, and that all the 

 explanations derived from these considerations are utterly errone- 

 ous. He has demonstrated, both theoretically and experimentally, 

 that the action of a circuit is equal to the sum of the electro-motive 

 forces divided by the sum of the resistances ; and that whatever be 

 the nature of the current, whether voltaic or thermo-electric, if this 

 quotient be equal, the effect is the same. He has also shown the 

 means of determining with accuracy the values of the separate re- 

 sistances and electro-motive forces in the circuit. The light which 

 these investigations has thrown on the theory of current electricity 

 is very considerable ; and although the labours of Ohm were, for 

 more than ten years, neglected, (Fischner being the only author who, 

 within that time, admitted and confirmed his views,) within the last 

 five years, Gauss, Leng, Jacobi, Poggendorfi^, Henry, and many 

 other eminent philosophers, have acknowledged the great value of 

 his researches, and their obligations to him in conducting their own 

 investigations. Had the works of Ohm been earlier known, and 

 their value recognised, the industry of experimentalists would have 

 been better rewarded. In this country those who have had most 

 experience in researches in which voltaic agency is concerned, have 

 borne the strongest testimony to the assistance they have derived 

 from this source, and to the invariable accuracy with which the ob- 

 served phenomena have corresponded with the theory of Ohm. This 

 accordance, it may be observed, is altogether independent of the 

 particular hypothesis which may be adopted as to the origin of elec- 

 tro-motive force ; and obtains equally, whether that force is regarded 

 as being derived from the contact of dissimilar metals, or as refer- 

 able to chemical agency. 



* 1. On the electric conductibility of the metals. (Schweigger's Journal, 

 second series, vol. xiv.) 



2. Experiments to discover the power of electro-magnetic multipliers. 

 (Ibid. vol. XXV.) 



3. Researches to ascertain the nature of unipolar conductors. (Ibid, vol, 

 xxix.) 



4. On hydro-electric currents. (Ibid, third series, vol. iii.) 



5. Statement of facts destroying the relations which have been confu- 

 sedly established between several galvanic properties, and particularly 

 hydro-electric conductors. (Ibid. vol. v.) 



6. Theory of galvanic currents. (Ibid, vol, vii.) 



