PHYSICS AND NATURAL HISTORY, OF GENEVA. 271 



English, one Italian, one Swedish, one from Holland, aud one a Bel- 

 gian. 



Augustin Pyramns de Caudolle has written almost a third of the 

 work, 4:,30o pages; Alph. de Caudolle, 1,387 pages ; J. Miiller, of Ar- 

 govie, 1,144:; Beutham, 1,133 ; Meissuer, 835 ; Dunal, 732; the twenty- 

 nine other assistants, articles less extended. De CandoUe, his sou, aud 

 his grandson (Oasimir) have compiled 5,947 pages out of the whole 

 13,194. The coutributors residing at Geneva have furnished sis-tenths. 



The mere correction of proof in such an especial worli has been a 

 great labor for the two directors, who have done it all themselves. They 

 have also greatly assisted their colaborers, by taking notes for sixty 

 years, without interruption, of all new descriptions aud plates which 

 have appeared in botanical books and journals. These notes, chissed 

 by families, form the most complete repertory of descriptive botanical 

 literature ever compiled. 



Several motives induced M. de Candolle not to extend the Prodro- 

 mus beyond the Dicotyledons. The principal one was the great increase 

 in the difficulty of the work, on account of the continually-increasing 

 number of specimens to be examined and of species aud characteristics 

 to be determined by the aid of the magnifying-glass. When A. P. de 

 Candolle commenced, an active botanist could describe, according to 

 the custom of the time, 1,500 or 1,800 species a year. Now, with the 

 work prepared as in the last volumes of the Prodromus, aud in ac- 

 cordance with the existing state of science, an industrious botanist could 

 describe not more than 300 or 400 species a year. The difficulty of ob- 

 taining the manuscripts at the time promised by the authors was 

 another great obstacle. To this cause must be attributed the delay in 

 the publication of the Prodromus, the volumes having appeared more 

 and more slowly in proportion as the number of writers was increased. 



The execution of this magniticent work has required fifty years, 

 indeed sixty, if we go back to its origin. It has employed three gen- 

 erations of the same family, which is an unusual circumstance in the 

 history of science, and will forever associate the name of Candolle with 

 the most remarkable scientific achievements of Geneva. 



