[The original has not been located. This is from the published version in the Philosophical Magazine, s. 3 v. 22 no. 145, April 1843, pp. 297-298.]
On the Iodide of Mercury. By H. F. Talbot, Esq., F.R.S., &c
To the Editor of the Philosophical Magazine.
Dear Sir,
Give me leave to reply in a few words to some remarks inserted in the last Number of your Journal. I will not occupy much of your space in so doing, for this appear to me to be really a very simple case. It is a mere question of dates, and nothing else.
Finding a paper inserted in your Journal, describing chemical and optical phænomena which appeared to be almost exactly the same with what I had published six years previously, I took the liberty of calling your attention to it. At the same time I carefully discriminated, as being "a fact both new and important," the phænomenon described in the latter part of the paper, since it was different from anything which I had observed. I am at a loss to know why objection should be taken to such a communication as this. It was simply a claim of scientific justice, such as inevitably must frequently be made in these days of unexampled activity in experimental research; for no one can possibly be expected to read and remember all that is published in the journal of science at home and abroad. Mistakes are therefore continually occurring. Discoveries already made are again published as new. When this happens, no other course is open than to point out the error, and to correct it in as few words as possible. This is what I intended to do, and it was my only object in addressing to you my short letter on the subject. The credit that may be due to any scientific discovery, whatever it may be, ought assuredly to be awarded to the first discoverer, and that with all the care and correctness that is possible; and I am quite ready and willing to see this principle fairly and impartially applied in all cases - more particularly in the present one.
Mr. W. <1> has satisfactorily shown that the very pretty phænomenon of the iodide of mercury was first observed by Mr. Hayes, an American chemist, who published it fourteen years ago in Silliman's Journal. <2> By all means then in future let it be ascribed to Mr. Hayes. It is to be regretted that his claim was not sooner mentioned; but I suppose that no one was aware of it.
I have referred to the page indicated of the American journal, but I find nothing more there that has reference to this particular subject. Mr. Hayes does not appear to have noticed the definite form and rectilinear boundaries of the scarlet portions of the crystal; which fact adds something, I think, to the argument, that the change of colour is owing to molecular displacement, and not to the loss or gain of any substance whatever.
With respect to the very different phænomenon seen in the iodide of lead, I believe that if any chemist would take the trouble to ascertain exactly what passes during its rapid transformation, this could not fail to be a valuable contribution to science; for at present it remains one of the most enigmatic facts in crystallography.
H. F. Talbot.
London,
March 11, 1843
Notes:
1. Robert Warington, Secretary to the Chemical Society, 'On the Biniodide of Mercury', to the editors of the Philosophical Magazine and Journal.
2. Also known as American Journal of Science and Arts, founded in 1818 by Benjamin Silliman.