My dear Sir,

I ought to have written to you long before now, but I am sorry to say I was laid up again with a new attack of pleurisy and pneumony. Now it is over and I feel again pretty well. In about four weeks I shall start for Edinburgh and I hope to be in London between the 16^th. to 20^th. April.¹

The publisher, Mr Koch, thinks it would be very good, to collect all your works in one collected edition. I proposed him to divide the “Works of Ch Darwin’ in this way: I General subjects. 1. The Voyage round the World, 2 Origin of Species, 3. Variation

II Zoology: 1. Descent of Man, 2. Expression

III Botany: 1. Orchids and Climbing Plants²

2 Drosera and the articles on Primula, Catasetum and so on, in sofar as they are not contained in any other work

IV Geology: 1. Geolog. Observations on South America

2. Volcanic Islands,

3. Coral reefs.

The proper division into Volumes depends on the size of the different writings to be taken together. Perhaps it might be very desirable to add to the first Series (General) a Volume containing the first Papers and Letters (1858, Linn. Soc.³ etc.— ? Letters from the Athenaeum, Nature etc)—

Mr Koch is very anxious to know what your opinion is about his plan. Most of your works are published by him. The Voyage does not make any difficulty.⁴ The geological writings have never been translated as yet. The only outward change of the books would be, to add a second, general, title. Should you approve of this edition, you would perhaps be so kind as to give me some hints with respect to papers of minor size, which might be added or collected, so as to give with the edition as it were a complete history of your work.

You asked me about the number of copies of your works sold in Germany, or sold in the German translation (for, a certain number sells always in the Baltic provinces, in Denmark and so on).⁵ Here is M^r Koch’s list (up to Febr 1^st.)

(That is in a round sum 17,000 copies)

I think there are few books which are bought in equal numbers in Germany, as our public does not buy books half as freely as the English.

With the best wishes for your health | I am | My dear Sir, | Yours sincerely. | J. Victor Carus