Faraday to James Thomson   15 November 1858

[Royal Institution embossed letterhead] | Albemarle St W. | 15 Novr. 1858

My dear Sir

I am much obliged by your note¹ - I happen to be occupied in collecting my papers (not electrical) into a volume²; & on reprinting the notice on ice from the Athenaeum³ have added a further development of my views⁴:- it will come out in the course of the winter I dare say; but that is as the printer likes[.]

You represent that my view gives no account of the beginning of regelation. That is not so great a difficulty to my mind as to yours; because, since the year 1833, if not before that time, I have been obliged to admit that particles cannot be so exclusively engaged, even by a combining chemical action, as to be indifferent to, or without relation, to those along side of them-

I will mention a difficulty as regards this beginning of regelation which occurs to me under your view; If the particles be supposed to be without this external relation.- You admit with me that bodies tend to retain that state which they for the time possess; and, that against a change of temperature of many degrees of heat:- then how can the small change of temperature not amounting to the 1/100th of a degree, due to difference of pressure in many of the regelation experiments, cause that change from solid to fluid or fluid to solid, which many degrees of temperature change, applied in the common way, will not effect?

It seems that in ice the melting temperature is irregular; i.e. that certain portions of the ice tend to melt before other portions. I have given my view of this irregularity in a note, which Tyndal[l] has added to his last paper in the Phil Trans⁵ - If ice of equal purity should either from crystalline arrangement or some other cause, prove to be a mixture of particles having differences in their fusibility, then it would be very easy to build up a fourth theory of regelation.- But time - reconsideration - new thoughts & new experiments will no doubt clear up all these matters.

Ever My dear Sir | Very Truly Yours | M. Faraday

Prof. Jas. Thomson | &c &c &c