316 LOUIS AGASSIZ. 



Fragments," but a new and wholly different 

 work. The thirty-five sheets of the last vol- 

 ume are printed, but the two volumes will 

 only be issued together. You can judge of 

 the difficulty of printing at Paris and correct- 

 ing proofs here, at Poretz or at Toplitz. I 

 am just now beginning to print the first num- 

 ber of my physics of the world, under the 

 title of " Cosmos : " in German, " Ideen zur 

 einer physischsn Weltbeschreibung." It is 

 in no sense a reproduction of the lectures I 

 gave here. The subject is the same, but the 

 presentation does not at all recall the form of 

 a popular course. As a book, it has a some- 

 what graver and more elevated style. A 

 " spoken book " is always a poor book, just 

 as lectures read are poor however well pre- 

 pared. Published courses of lectures are my 

 detestation. Cotta is also printing a volume 

 of mine in German, " Physikalische geogra- 

 phische Erinnerungen." Many unpublished 

 things concerning the volcanoes of the Andes, 

 about currents, etc. And all this at the age 

 when one begins to petrify ! It is very rash ! 

 May this letter prove to you and to Madame 

 Agassiz that I am petrifying only at the ex- 

 tremities, the heart is still warm. Ketain 

 for me the affection which I hold so dear. 



A. DE HUMBOLDT. 



