Faraday to Charles-Gaspard De La Rive   9 October 1822

Royal Institution | Octr. 9th 1822

My dear Sir

I received your kind letter¹ on Saturday and finding that Dr. Marcet is even now preparing to leave London I am anxious to write to you by him although I have time only for a short Letter for Dr. M. requests to have it immediately. I was half afraid you had forgotten me and then again I was half in hopes that you were so busy in the pursuit of science that you had not time to think of me. I am glad indeed on both accounts to find the latter true and am very anxious to see the full account of your experiments[.] I am delighted with them not only because they correct opinions which were before generally received and make them more in accordance with natural phenomena but also because they serve as a vindication to myself for the doubts or rather for the reserve I have entertained respecting M Ampere’s theory in its fullest extent[.] Its beauty I admire but I have been unwilling to admit it into my own mind to a rank with those theories in other branches of physical science which are accompanied continually by experimental proofs because though it accords pretty well with most if not all the phenomena yet there are many parts in it that seem to be mere assumption. I expressed not many days since to M Ampere my persuasion that there were an immense number of facts still to be made out between the place to which actual experiment has brought us and the extent of his theory and your experiments come very opportunely to strengthen that persuasion²[.]

I have really been ashamed sometimes of my difficulty in receiving evidence urged forward in support of opinions on electro magnetism but when I confess my want of mathematical knowledge and see mathematicians themselves differing about the validity of arguments used it will serve as my apology for waiting for experiment[.]

M Amperes experiments which you mention are I think very important especially that of the production of magnetism in a piece of copper by mere vicinity to a voltaic circuit without actual connection with it[.] I am glad to find M. Ampere has modified the view he took of my little expt of apparent loss of weight and that his present opinion coincides so nearly with mine³[.] I remember in my note of E Mag motions I stated the effect to be “equivalent to a diminution of the cohesive attraction of the mercury.”⁴ I hope he will make out & support the idea of a repulsion in the whole length of the current.

I intend to send one of our papers on Steel by Dr. Marcet and we beg your acceptance of it - I find on looking for it the paper on Electro Magnetical apparatus & and Note on new E. Mag. motions which I thought I had sent you but the name & dust on the outside makes me afraid I have never done so[.] This makes me conclude I have not sent you the paper on the third Chloride of Carbon by Mr. Phillips & myself and I therefore put it into the packet begging that you will receive them as marks of my anxiety to shew you respect⁵.

You kindly mention that I may make what use of the facts you mention in your letter that I please[.] Had I any thing to do with the Journal of Science &c I should gladly have availed myself of the liberty[.] But I have nothing to do with it not even with the Miscellanea now and I am anxious you should know this. There have been many things in the form or reviews observations &c that have appeared it in wh<<ich>> were very adverse to my feelings and I am desirous that ther<<e>> should not be the least chance of your attributing any <<of>> the kind to me[.] For the future do not consider me as having a<<ny>> thing to do with any articles but such as have either my name or my initials to them.

I have not a particle of news to send you but I hope for some[.] I am at present making a few expts on vapour with reference to the short paper of mine which you have probably seen in the Annales de Chimie and the observations by M Gay Lussac upon it⁶[.] I have been surprised by his remark on the temperature of vapour from saline solutions & so have most of the chemists I have mentioned it to. However I find the point a nice once to determine experimentally but think I now have unexceptionable means⁷. Now that I know how to send to you I dare say I shall often trouble you[.]

I am dear Sir With great respect | Your Obedient & faithful | M. Faraday