To J. D. Hooker   1 September [1859]

My dear Hooker

I know of nothing as a guide to speculating on the effects of mingling two floras. Your case seems extremely curious.—

I am not surprised at your finding your Introduction very difficult. But do not grudge the labour & do not say that you “have burnt your fingers” & are “deep in the mud”; for I feel sure that the result will be well worth the labour. Unless I am a fool, I must be a judge to some extent of the value of such general Essays, & I am fully convinced that yours are the most valuable ever published.—

I have corrected all but 2 last chapters of my Book & hope to have done Revises & all in about 3 weeks, & then I (or we all) shall start for some months Hydropathy. My health has been very bad; & I am becoming as weak as a child, & incapable of doing anything whatever except my 3 hours daily work at Proof-sheets.— God knows whether I shall ever be good for anything again—perhaps a long rest & hydropathy may do something.

I have not had A. Grays Essay,¹ & sh^d. not feel up to criticise it, even if I had the impertinence & courage. You will believe me that I speak strictly the truth when I say that your Australian Essay is extremely interesting to me,—rather too much so— I enjoy reading it over & if you think my criticisms are worth anything to you, I beg you to send the sheets (if you can give me time for good days); but unless I can render you any little, however little, assistance, I would rather read the Essay when published. Pray understand that I sh^d. be truly vexed not to read them, if you wish it for your own sake.

I had a terrible long fit of vomiting yesterday, which makes the world rather extra gloomy today. And I have an insanely strong wish to finish my accursed Book,—such corrections every page has required, as I never saw before. It is so weariful killing the whole afternoon after 12 oclock doing nothing whatever. But I will grumble no more.— So farewell, we shall meet in the winter I trust.

Farewell | My dear Hooker | Your affect. friend | C. Darwin