William Whewell to Faraday   25 April 1834

Trinity College, Cambridge April 25, 1834

My dear Sir,

I was glad on several accounts to receive your letter¹. I had the pleasure of being present at the R.S. at the reading of your paper, in which you introduced some of the terms which you mention², and I was rejoiced to hear them, for I saw or thought I saw that these novelties had been forced upon you by the novelty of extent and the new relations of your views. In cases where such causes operate new terms inevitably arise, and it is very fortunate when those upon whom the introduction of these devolves look forwards as carefully as you do to the general bearing and future prospects of the subject; and it is an additional advantage when they humour philologists so far as to avoid gross incongruities of language. I was well satisfied with most of the terms that you mention; and shall be glad and gratified to assist in freeing them from false assumptions and implications, as well as from philological mon‑strosities.

I have considered the two terms you want to substitute for eisode and exode ³, and upon the whole I am disposed to recommend instead of them anode and cathode ⁴; these words may signify eastern and western way, just as well as the longer compounds which you mention, which derive their meaning from words implying rising and setting, notions which anode and cathode imply more simply. But I will add that as your object appears to me to be to indicate opposition of direction without assuming any hypothesis which may hereafter turn out to be false, up and down, which must be arbitrary consequences of position on any hypothesis, seem to be free from inconvenience, even in their simplest sense. I may mention too that anodos and cathodos are good genuine Greek words, and not compounds coined for the purpose. If however you are not satisfied with these, I will propose to you one or two other pairs. For instance dexiode[*] and sceode (skaiode[*] if you prefer it) may be used to indicate east and west, agreeably to Greek notions and usage, though their original meaning would be right and left; but I should say in this case also, that right and left, as it cannot be interpreted to imply a false theory, any more than east and west, would be blameless for your object. Another pair orthode and anthode, which mean direct and opposite way, might be employed; but I allow that in these you come nearer to an implied theory. Upon the whole I think anode and cathode much the best.

I have already said that I liked most of your new words very well, but there is one which I should be disposed to except from this praise; I mean zetode. My objections are these. This word being grouped with others of the same termina‑tion might be expected to indicate a modification of electrode, as eisode, and exode, or anode and cathode do. Instead of this it means a notion altogether heterogeneous to these, and the ode is here the object of a verb zete, contrary to the analogy of all the other words. It appears to me that as what you mean is an element, all that you want is some word which implies an element of a composition, taking a new word however, in order that it may be recollected that the decomposition of which you speak is of a peculiar kind, namely electrolytical decomposition. Perhaps the Greek word stecheon (or stoicheion ⁵) would answer the purpose. It has already a place in our scientific language in the term stoecheiometry; and has also this analogy in its favour that whereas your other words in ode mean ways, this word stecheon[*] is derived from a word which signifies to go in a row. The elements or zetodes are two things which go or seek to go, opposite ways. I might add that if you want a word which has a reference to your other terms, the reference must be to the process of decomposition by which these elements are obtained. You might call your zetode, an electrostecheon, especially if you had occasion to distinguish these elements obtained by electrolytical processes from others obtained by chemolytical processes, that is, the common analysis effected by the play of affinities. Elements obtained in the latter way might be called chemostecheons in opposition to electrostecheons. But I am afraid I am here venturing beyond my commission and out of my depth; and you must judge whether your stecheons or zetodes, or whatever they are to be, are likely to require the indication of such relations. If you were to take anode and cathode and adopt stecheon, I think anastecheon and catastecheon might indicate the two stecheons. If you stick to zetode anazetode and catazetode would be the proper terms but perhaps zetanode and zetocathode would be more analogous to zetode, which is a word that, as I have said, I do not much like.

My letter is become so long that I will recapitulate: anode, cathode, zetanode, zetocathode fulfil your requisitions; anode, cathode, anastecheon, catastecheon are what I prefer. With great interest in your speculations and best wishes

Believe me, yoursávery truly W. Whewell

[*] These letters are boxed in pencil, presumably by Faraday who adopted these particular terms in his reply, letter 714.

Address: Michael Faraday Esq | Royal Institution | Albemarle Street | London