To C. G. Ehrenberg   25[–31?] March [1846]¹

Dear & highly Honoured Sir

I received your kind letter two days ago, & beg to thank you sincerely for the information contained in it.—² Herewith I send a copy of my little paper on the Atlantic Dust,³ (published in the Geolog. Journal) & which I would have sent ere this, had I supposed you would have cared to see it.— I have asked the Hydrographer to the Admiralty (Capt. Beaufort) to call the attention of Officers to the dust & to collect specimens of it. I have no specimens myself of grasses from Ascension but I have written to D^r. Hooker & I well know he will proud to send you specimens if he has them: I doubt, however, whether he has yet named his grasses. Sometime ago I sent you some specimens (through the Chev. Bunsen)⁴ of rocks of the Secondary period from the Cordillera; sh^d you have examined them I sh^d esteem it a great favour to know the result.—

I regret much to hear of the long illness in your family: being a married man myself, I can appreciate your distress.

Pray believe me, dear Sir, with much respect. | Yours faithfully & obliged | C. Darwin

P.S. | I have received the Ascension plants from D^r. J. D. Hooker for you.—⁵ I enclose his note, as you might like to see the scanty list of really indigenous Phaneragam: plants.— You will observe there is only one certainly indigenous grass, or at most two.— Many plants have been of late introduced there.—