Darwin Correspondence Project

Down, Bromley, Kent

Dec: 12th.

Dear Cresy

Thank you much for your most interesting note. I have ordered a Chemical News.—   I particularly beg you to give Dr. A. Taylor my cordial thanks for his note full of valuable suggestions. After writing out the greater part of my paper on Drosera, I thought of so many points to try and I wished to re-test the basis of one large set of experiments, namely to feel still more sure than I am, that drop of plain water never produces any effect, that I have resolved to publish nothing this year.— For I found in record of my daily experiments one suspicious case.— I must wait till next summer. It will be difficult to try any solid substance containing nitrogen, such as ivory; for two quite distinct causes excite the movement, namely mechanical irritation and presence of nitrogen. When a solid substance is placed on leaf it becomes clasped, but is released sooner than when a nitrogenous solid is clasped; yet it is difficult (except with raw meat and flies) to be sure of the result owing to differences in vigour of different plants. The last experiments which I tried before my plants became too languid are very curious, and were tried by putting microscopical atoms on the gland itself of single hairs; and it is perfectly evident that an atom of human hair 1/76,000 of a grain (as ascertained by weighing a length of hair) in weight, causes conspicuous movement. I do not believe (for atoms of cotton thread acted) it is the chemical nature; and some reasons make me doubt whether it is actual weight; it is not the shadow and I am at present, after many experiments, confounded to know what the cause is. That these atoms did really act and alter the state of the contents of all the cells in the glandular hair, which moved, was perfectly clear. But I hope next summer to make out a good deal more.—

I have been much interested by your account of your discussion, and I thank you as a bold and true Defender of the Faith. It is very interesting to hear of such discussions going on in London on scientific questions out of the regular Societies. I am much pleased at all that you tell me. The article in National is by Carpenter. I am pleased that you were struck by the ``Snakes'' in Huxley's article; it seemed capital to me.— Dr. Bree is nobody scientifically. His book is a mass of misrepresentations and blunders. By far, in my opinion, the best Review is by Asa Gray in Atlantic Monthly in U. States. If you cared to see it, I could lend it you. I am very hard at work in preparing a corrected Edit. of the Origin (for Murray sold at sale 400 more copies than he has). I shall not allude to any Reviews, but so far profit as to expand where I have been most misunderstood, and add several considerable discussions on points which I formerly ought to have noticed. I will send you a copy when it is out.

Thanks for advice about transitional cases. Excuse this rather hurried note, and with cordial thanks for all your great kindness

Yours very sincerely | C. Darwin

My daughter very slowly, but steadily improves in health.