The Evolution of Electric and Magnetic Physics. 157 



said that all physical science is measurement. It is meas- 

 urement that distinguishes science from vague theorizing. 

 Just as Franklin founded the art, Coulomb and Cavendish 

 founded the quantitative science of electricity, as distin- 

 guished from purely experimental or qualitative knowledge. 

 This branch of the subject next received special cultivation 

 at the hands of the French savants in the Napoleonic period. 



The task of developing electrical knowledge had hitherto 

 been one of acquiring facts by direct experiment, but at this 

 time it naturally divided between two different sets of work- 

 ers. There now sprang up a set of electrical philosophers 

 who theorized upon the facts already known. One of these 

 classes continued as before to seek for new facts and new 

 discoveries by direct experiment, continually varying their 

 cross-examination of Nature ; the other party took the facts 

 already gleaned, submitted them to analysis, and determined 

 mathematically the laws those facts uttered. By a continua- 

 tion of the same process, they endeavored to determine new 

 facts and more recondite laws by mathematical reasoning 

 from the existing premises. As leaders of these parties, 

 Faraday might be cited for the first, Clerk-Maxwell of the 

 second. Much futile controversy has been waged as to the 

 power, advantage, and rank of these two schools. Both are 

 necessary ; the one supplements and corrects the work of the 

 other, for it is impossible to apply intelligent labor to the 

 vanguard of science in any direction without gaining ground. 

 The danger of the method of the experimental school, when 

 carried to extremes, is loss of labor by groping without defi- 

 nite object in the dark, lacking competent leadership ; the 

 danger of over-impetuous activity in the analytical camp is 

 in missing truth, through the assumption that all the neces- 

 sary premises are already known, or else in terminating re- 

 search with mere symbols pure mathematics, instead of 

 physics written in mathematical language forgetting the 

 significance of the symbols and losing the grasp they hold 

 on facts. The best successes are generally made by the co- 

 operation of both parties, for all observation must stand the 

 test of analytical trial, and all calculations must be confirmed 

 under the ordeal of experiment. 



Many improvements in methods and apparatus were made 

 after the date of Franklin's discoveries, but the next great 

 epoch was the discovery of galvanic electricity by Galvani, 

 of Bologna, in 1786. An electrical machine was being 

 worked in a room where some frogs were being dissected. 



