THE ASTRONOMICAL VIEW OF NATURE. 363 



The extension and confirmation which the Newtonian 

 attraction formula had thus gained in the minds of 

 many seemed to be entirely upset by a series of dis- 

 coveries in which electrical, and subsequently magnetic, 

 phenomena played an important part. These were, the 

 discovery of galvanic electricity by Galvani in 1791 and 

 by Volta in 1800 ; of the physiological and chemical 

 effects of this form of electricity, especially by Davy 

 (1806); of the magnetic effect of moving electricity by 

 Oersted in 1820; of the connection of heat and elec- 

 tricity by Seebeck in 1822; of induction by Faraday in 

 1831 i.e., of the action of electric currents and magnets 

 in generating other electric currents or magnetic effects 

 in bodies which are moving in their neighbourhood; and, 

 finally, of diamagnetism by Faraday in 1845. 



Many of the celebrated men with whose names the mod- 36. 



... Davy and 



ern discoveries m electricity are identified, and amongst Faraday, 

 them notably Davy and Faraday, were not brought up 

 in the mathematical school of the Continent,^ in which 



sion suivant une loi quelconque ne j humous papers (edited by Max- 

 doit etre regardee que comme une ' well in 1879 under the title of 

 formule qui exprime un re.sultat ' The Electrical Researches of the 

 d'experience " (vol. i. p. 297). Hon. Henry Cavendish') he anti- 

 ^ To these mu.st be added the ' cipated, as Maxwell has shown, 

 name of Cavendish (1731-1810), i many later investigations of British 

 whose electrical researches, in ; and Continental writers. He had 

 which he anticipated many of Cou- ] a clear notion of electrical capacity, 

 lomb's results, proceeded on en- of potential and of electrical resist- 

 tirely different lines from those of > ance, he anticipated Ohm's law- 



the Continental school. He proved 

 in or before 1773 from the fact 

 that a small globe' situated in the 



i.e., the proportionality between 

 the electro -motive force and the 

 current in the same conductor. 



hollow of a large electrified globe ; He studied the properties of diel- 

 and communicating with it showed , ectrics, and " not only anticipated 

 no signs of electricity, that electric i Faraday's discovery of the specific 



attraction and repulsion must be 

 inversely as the square of the dis- 

 tance. In his published and post- 



inductive capacity of different sub- 

 stances, but measured its numer- 

 ical value in several substances " 



