86 Frqf. Clerk Maxivell, On the unjmblished . [Nov. 5, 



November 5, 1877. 

 Peof. Cayley, Vice-president, in the chair. 



The following communication was made to the Society by 



Prof. Clerk Maxwe": l, 0?^ the unpublished electrical papers 

 of the Hon. Henry Cavendish. 



Cavendish published only two papers relating to electricity, 

 "An attempt to explain some of the principal Phsenomena of 

 Electricity by Means of an Elastic Fluid " [Fhil. Ti'ans. 1771, 

 pp. 584 — 677], and "An account of some Attempts to imitate 

 the Effects of the Torpedo by Electricity " [Phil, Trans, for 

 1776, pp. 196 — 225]. He left behind him, however, some twenty 

 packets of manuscript on mathematical and experimental elec- 

 tricity. These were placed by the then Earl of Burlington, now 

 Duke of Devonshire, in the hands of the late Sir William Snow 

 Harris, who appears to have made "an abstract of them with 

 a commentary of great value on their contents." This was sent 

 to Dr George Wilson when he was preparing his Life of Cavendish 

 {Works of the Cavendish Society, Yo\. i. London, 1851). It was 

 afterwards returned to Sir W. S. Harris, but I have not been 

 able to learn whether it is still in existence. The Cavendish 

 manuscripts, however, were placed in my hands by the Duke 

 of Devonshire in 1874, and they are now almost ready for 

 publication. 



They may be divided into three classes : 



(A) Mathematical propositions, intended to follow those in 

 the paper of 1771, and numbered accordingly. Some of these 

 are important as showing the clear ideas of Cavendish with 

 respect to what we now call charge, potential, and the capacity 

 of a conductor; but the great improvements in the mathematical 

 treatment of electricity since the time of Cavendish have rendered 

 others superfluous. 



We come next to an account of the experiments on which 

 the mathematical theory was founded. This is a manuscript 

 fully prepared for the press, and since it refers to the second part 

 of the published paper of 1771 as " the second part of this Work," 

 it must have been intended to be published as a book, along with 

 a reprint of that paper. It contains no dates, but as it refers to 

 experiments which we know were made in 1773, it must have 

 been written after that time, but I do not think later than 1775. 



It forms a scientifically arranged treatise on electricity. A 



