I was delighted with your letter in which you touch on Slavery; I wish the same feelings had been apparent in your published discussion. But I will not write on this subject, I should perhaps annoy you, and most certainly myself. I have exhaled myself with a paragraph or two in my Journal on the sin of Brazilian slavery; you perhaps will think that it is in answer to you; but such is not the case. I have remarked on nothing which I did not hear on the coast of South America. My few sentences, however, are merely an explosion of feeling. How could you relate so placidly that atrocious sentiment (In the passage referred to, Lyell does not give his own views, but those of a planter.) about separating children from their parents; and in the next page speak of being distressed at the whites not having prospered; I assure you the contrast made me exclaim out. But I have broken my intention, and so no more on this odious deadly subject.
There is a favourable, but not strong enough review on you, in the "Gardeners' Chronicle". I am sorry to see that Lindley abides by the carbonic acid gas theory. By the way, I was much pleased by Lindley picking out my extinction paragraphs and giving them uncurtailed. To my mind, putting the comparative rarity of existing species in the same category with extinction has removed a great weight; though of course it does not explain anything, it shows that until we can explain comparative rarity, we ought not to feel any surprise at not explaining extinction...
I am much pleased to hear of the call for a new edition of the 'Principles': what glorious good that work has done. I fear this time you will not be amongst the old rocks; how I shall rejoice to live to see you publish and discover another stage below the Silurian—it would be the grandest step possible, I think. I am very glad to hear what progress Bunbury is making in fossil Botany; there is a fine hiatus for him to fill up in this country. I will certainly call on him this winter...From what little I saw of him, I can quite believe everything which you say of his talents...
CHARLES DARWIN TO J.D. HOOKER. Shrewsbury [1845?].