John Percy to Faraday   18 April 1845

Birmingham, April 18 | 1845

My dear Sir

I write to ask your opinion on one point, and I must apologise for doing so, knowing the value of your time. We have noticed a thousand times the grass in the winter exposed frequently to a cold many degrees below the freezing point. We know that grass contains a large quantity of water. But, although the grass may be exposed to cold sufficiently intense rapidly to freeze water under ordinary circumstances, yet the water in that grass, so far as I have casually remarked, does not appear to freeze when exposed to a considerable degree of cold. And when we consider the structure of a leaf, we should be inclined to conclude, that, if the water became solid, the structure of the leaf would be impaired. Now the point concerning which I take the liberty of interrogating you is this, - whether water may not, when inclosed in extremely minute tubes, say as fine as a hair, remain liquid at the ordinary temperature of congelation. I have made a few experiments on this point with glass tubes drawn out as fine as a hair; and it appeared to me that extreme tenuity of the tube exercised a retarding effect upon the freezing of water contained in them. But I make the statement with great caution, as I have not satisfied myself of its correctness by frequent repetition. With best compliments to Mrs Faraday, in which Mrs. Percy¹ desires to unite,

I remain, my dear Sir, | With great respect, | Yours sincerely | John Percy.

P.S. There is yet much for you to see in & about Birmingham, & any time you feel disposed to travel this way we shall be delighted to entertain you in our informal manner.