190 NOTICES OF BOOKS. 
adopted, and much of the contents printed, before its author had seen 
a copy of the only publication which, as yet, bears the title of a Cybele. 
The general scope and character of the work before us, probably, 
may be better shown by a nearly literal translation of some selected 
passages, than by any attempt to give a condensed view of the essay 
as a whole; while the elaborate copiousness of detail renders an 
abstract of contents quite incompatible with the ordinary limits of a 
book-notice. M. Thurmann appropriately dedicates his work to Mr. 
Charles Martins, who has accomplished so much as a scientifie traveller 
and philosophical inquirer. 
* Botanical geography," writes the author, “shows the facts of 
vegetable dispersion, and brings them into relation with their causes." 
. . . - “ Botanical geography in its different parts is a science in 
course of formation. Phytography, climatology, geology, physics, 
chemistry, agriculture, fast bring to it their contingent of facts, which 
will one day be combined into a body of science, at present scarcely 
traced in outline. Meantime, it is very difficult to unite the scat- 
tered data, and bring them to bear upon one common point which is 
sought to be elucidated.” (Preface, pp. vii. and ix.) 
* Having travelled over some part of the chain of the Jura, from 
geological interest, each summer during upwards of fifteen years, I 
have been enabled, at the same time, to collect together a consider- 
able store of data concerning its flora and the general characters 
of its vegetation. While visiting the neighbouring countries I was 
struck by the contrasts they offer with the Jura in these respects, and 
was naturally led to seek how far these contrasts correspond with the 
. differences of soil which were the first object of my attention. I soon 
perceived that all the observed facts tended to establish the influence 
of the subjacent rocks on the distribution of the species, At first, I 
regarded this influence as arising from their chemical composition, and 
long saw only through the medium of this fixed idea, founded upon a 
number of specious appearances. Researches that I made to confirm 
. this opinion, however, awakened doubts in my mind, and finally led 
me to a result directly opposed to that which I expected. 1 was 
. forced to acknowledge in the state of aggregation of the subjacent 
. rocks, the principal cause of the differences which I had attributed to 
. their composition. Such, in few words, is the history of this work. 
. To give a sufficiently complete view of the vegetation of the Jura 
