82 Britain's Heritage of Science 



interior, it can only be a small fraction. Fortunately the 

 manuscripts of Cavendish's electrical experiments have been 

 preserved, and were placed in the hands of Clerk Maxwell 

 when he took over the Professorship of Experimental Physics 

 at Cambridge. Their subsequent publication throws quite 

 a new light on Cavendish's importance as a physicist, giving 

 evidence of a wonderfully balanced combination of theoretical 

 power and experimental skill. Adverting to the many 

 instances in which Cavendish neglected to publish results of 

 importance, Maxwell 1 remarks : 



" Cavendish cared more for investigation than for 

 publi cation. He would undertake the most laborious 

 researches in order to clear up a difficulty which no one 

 but himself could appreciate, or was even aware of, and 

 we cannot doubt that the result of his enquiries, when 

 successful, gave him a certain degree of satisfaction. 

 But it did not excite in him that desire to communicate 

 the discovery to others which, in the case of ordinary men 

 of science, generally ensures the publication of their 

 results. How completely these researches of Cavendish 

 remained unknown to other men of science is shown by 

 the external history of electricity." 



This is not the place to enter into the details of the various 

 researches which were edited by Maxwell in 1879. Suffice 

 it to say that Cavendish measured experimentally the 

 electrostatic capacity of bodies, anticipating Faraday in the 

 discovery of the difference of the inductive capacities of 

 various substances, and Ohm in showing that the electric 

 current is proportional to the electromotive force. He also 

 compared the electric resistance of iron with that of rain 

 water and of different salt solutions. All this was done 

 by means of a rough electroscope and without a galvanometer. 

 He converted, in fact, his nervous system into a galvanometer, 

 by comparing the electric shocks received when Ley den jars 

 were discharged through various conductors, altering the 

 length of the conductors until the shocks were estimated 

 to be equal. He obtained astonishingly accurate results 

 with such simple and almost primitive means. 



J " The Electrical Researches of the Hon. Henry Cavendish," 

 Introduction, p. xlv. 



