Faraday to Charles-Gaspard De La Rive   20 April 1820

Royal Institution | April 20th 1820

Dear Sir

I never in my life felt such difficulty in answering a letter as I do at this moment your very kind one of last year. I was delighted on receiving it to find that you had honored me with any of your thoughts and that you would permit me to correspond with you by letter[.] But I fear that my intention of meriting that honor has already made me unworthy of it for whilst waiting continually for any scientific news that might arise to send you I have delayed my answer so long as almost to forfeit the right of permission to send one at all[.] I hope you will attribute my tardiness to its right motive, diffidence of my worthiness to write to you; and that it will not injure me in your estimation. I will promise if you still grant me the liberty of correspondence never to err so again[.]

I am the more ashamed of my neglect because it is a neglect of gratitude as well as of respect. I am deeply indebted to you for your kind expressions respecting my paper on sonorous tubes¹ and its value is very much increased with me by your praise[.] I regret however on the same subject that you should imagine I thought but little of your experiment with mercury². I made it immediately and was very much surprised by it and I only refrained from noticing it because I was afraid of myself and thought I should apply it wrongly and thus intrude on your subject without any right or reason. Indeed I had hopes that you would take up the subject again and after reviewing the various sonorous phenomena of different kinds as produced in different ways would undertake what I had not ventured to do namely to draw general conclusions and develope the laws to which they (the phenomena) were obedient.

You have honored me by many questions and no regret can be greater than mine that I have suffered time to answer them rather than myself - In every line of your kind letter I find cause to reproach myself for delay - The next I will answer more readily and the fear will be that I shall trouble you too often rather than too seldom[.]

You honor me by asking for scientific news and for any information of my own. I am sorry that both sources are very barren at present but I do hope that both will improve[.] Mr Stodart & myself have lately been engaged in a long series of experiments and trials on steel with the hope of improving it and I think we shall in some degree succeed we are still very much engaged in the subject but if you will give me leave I will when they are more complete which I expect will be shortly give you a few notes on them³. I succeeded by accident a few weeks ago in making artificial plumbago but not in useful masses. I had heated iron with charcoal dust two or three times over and in that way got a dark gray very crystalline carburet of Iron of I believe a definite composition but the outside of the button which had been long in close contact with the charcoal was converted into excellent plumbago. Since then I have observed amongst the casters of iron that when they cast on a facing of charcoal dust as is the case in fine work that the surface of [the] casting is frequently covered with a thin film of plumbago evidently formed in the same way as in the above experiment[.]

We have lately had some important trials for oil in this metropolis in which I with others have been engaged. They have given occasion for many experiments on oil and the discovery of some new and curious results. One of the trials only is finished and there are 4 or 5 more to come⁴[.] As soon as I can get time it is my intention to trace more closely what takes place in oil by heat and I hope to bribe you to continue to me the honor & pleasure of your correspondence by saying that if anything important turns up I will make it the matter of a letter.

I am My Dear Sir with the Highest respect Your Obliged & Humble | M. Faraday