To C. G. Ehrenberg 23 January 
Down near Bromley | Kent
Would you be so good, if convenient, to return to me, by Dr J. Hooker, who will be at Berlin in a fortnight, the short sketch, which I sent you, of the facts regarding the Atlantic dust, & which I thought, perhaps, worth inserting in some English Journal: if you have examined the other specimens of dust, would you be so good as to inform me, that I might refer to your descriptions in this sketch.1
Amongst the little packets, which I sent you, there were some of the earth of the Pampas, in which so many extinct mammifers are embedded, should you feel any interest on this subject, I should feel particularly thankful to hear the result of your examination. Should the subject not interest you, I should be sorry to think even of asking you to waste any of your time on it. There are, also, specimens of a singular white bed, (I now believe of a very fine tufaceous nature) which extends for hundreds of miles on the Patagonian coast, about which I am curious.
I beg to apologise for having thus troubled you, but might I further request you, should you see Dr Dieffenbach, kindly to take the trouble to ask him, to return me my copper-plate, woodcuts, & M.S. corrections for his German edition of my Journal, which I cannot get him to return to me, though I shall be thus put to considerable loss of time & money, in preparing a second English Edition.—2
Believe me dear Sir | With great respect | Your’s faithfully & obliged | C. Darwin To | Professor C. Ehrenberg | &c &c &c
Would like sketch returned [see 775].
Would be particularly thankful for result of CGE’s observations on earth of Pampas.
Asks that Ernst Dieffenbach return copperplate and woodcuts.
Please cite as
Darwin Correspondence Project, “Letter no. 819,” accessed on 13 February 2016, http://www.darwinproject.ac.uk/DCP-LETT-819