[ I ] 



INTRODUCTION* 



Oo little is known of the details of the life of Henry Cavendish, and so 

 fully have the few known facts been given in the Life of Cavendish by 

 Dr George Wilson f, that it is unnecessary here to repeat them except in 

 so far as they bear on the history of his electrical researches. 



He was born at Nice on the loth October, 1731; he became a Fellow 

 of the Royal Society in 1760, and was an active member of that body 

 during the rest of his life. He died at Clapham on the 24th February, 1810. 



His father was Lord Charles Cavendish, third son of William, second 

 Duke of Devonshire, who married Lady Anne Grey, fourth daughter of 

 the Duke of Kent. Henry was their eldest son. He had one brother, 

 Frederick, who died 23rd February, 1812. 



Of Lord Charles Cavendish we have the following notice by Dr 

 Franklin {. After describing an experiment of his on the passage of 

 electricity through glass when heated to 400 F., he says, " It were to be 

 wished that this noble philosopher would communicate more of his ex- 

 periments to the world, as he makes many, and with great accuracy." 



Lord Charles Cavendish has also recorded a very accurate series of 

 observations on the depression of mercury in glass tubes, and these have 

 furnished the basis not only for the correction of the reading of baro- 

 meters, &c., but for the verification of the theory of capillary action by 

 Young, Laplace, Poisson and Ivory. 



I think it right to notice the scientific work of Lord Charles Cavendish, 

 because Henry seems to have been living with him during the whole period 

 of his electrical researches. Some of the jottings of his electrical calcula- 

 tions are on torn backs of letters, one of which is addressed, 



[The Ho]n ble M r Cavendish 

 at the R 4 Hon ble 

 The L d Charles 

 Cavendish's 



Marlborough Street. 



* By the Editor [James Clerk Maxwell]. 



f Published in 1851 as the first volume of the Works of the Cavendish Society. 

 } Franklin's, Works, edited by Jared Sparks, Boston, 1856, vol. v. p. 383. See 

 also Note 26 at the end of this book. 

 Phil. Trans. 1776, p. 382. 

 c. P. I. I 



