of Magnetism hy Rotation. 289 



I shall abstain from making any other remark on Mr Bar- 

 low's gratuitous assumption, that during four years I took 

 no steps to observe the effects of rapid rotation, than that 

 such was not precisely the fact, though, from my not having 

 the means of keeping up the motion, J certainly did not de- 

 tect the eff*ect. Mr Barlow has farther stated, that he waited 

 Jive months for me to complete my paper before he sent his 

 own. I must reply to this, that his paper was read to the 

 Royal Society on the 5th May, and of course sent to the 

 secretary some time before ; and that, by the account of his 

 experiments, published in the Edinburgh Philosophical Jour- 

 nal for July 1825, which, though bearing the signature of 

 another person, must be supposed, having been transmitted 

 by him, to have had his sanction, it appears the experiments 

 described in that paper were not completed before February. 

 As Mr Barlow appears to be under some misapprehension 

 as to the nature of my general argument, when he supposes 

 I can imagine it will derive support from minute distinctions, 

 I shall state clearly that the principle for which I contend is, 

 that in any account of philosophical discoveries, where it may 

 be necessary to assign to several their respective shares in 

 those discoveries, the strictest impartiality should be observ- 

 ed ; that this ought especially to be the case where the ac- 

 count is anonymous ; but, above all, when one who claims a 

 share in them ventures so to become the author : And I fur- 

 ther hold, that such impartiality does not characterize the 

 article which was the origin of this correspondence. However 

 averse Mr Barlow may be to admit the necessity of this cor- 

 respondence, I am disposed to think it may possibly lead to 

 the exercise of greater caution in future communications. 



I remain. Dear Sir, 

 R. M. Academy, Yours very truly, 



^&h May 1827. S. H. Christie. 



P. S.- — I beg you will do me the favour to accept the ac- 

 companying copies of papers in the Transactions. That on 

 the repetition of my experiments by Mr Foster at Port Bowen 

 exhibits the effects of the rotation of an iron plate in the most 

 striking manner ; and if any thing were wanting to show, not 

 only how early I had observed these effects, but how much 



