Xll AUTHOR S PREFACE. 



of the science. My lectures were given extemporaneously, 

 both in French and German, and without the aid of written 

 notes, nor have I, in any way, made use, in the present work, 

 of those portions of my discourses which have been preserved 

 by the industry of certain attentive auditors. With the 

 exception of the first forty pages, the whole of the present 

 work was written, for the first time, in the years 1843 and 

 1844. 



A character of unity, freshness, and animation, must, I 

 think, be derived from an association with some definite 

 epoch, where the object of the writer is to delineate the pre- 

 sent condition of knowledge and opinions. Since the addi- 

 tions constantly made to the latter give rise to fundamental 

 changes in pre-existing views, my lectures and the Cosmos 

 have nothing in common beyond the succession in which 

 the various facts are treated. The first portion of my work 

 contains introductory considerations regarding the diversity 

 in the degrees of enjoyment to be derived from nature, 

 and the knowledge of the laws by which the universe is 

 governed ; it also considers the limitation and scientific mode 

 of treating a physical description of the universe ; and gives 

 a general picture of nature which contains a view of all the 

 phenomena comprised in the Cosmos. 



This general picture of nature, which embraces within its 

 wide scope the remotest nebulous spots, and the revolving 

 double stars in the regions of space, no less than the telluric 

 phenomena included under the department of the geography 

 of organic forms (such as plants, animals, and races of men), 

 comprises all that I deem most specially important with 

 regard to the connection existing between generalities and 

 specialities, whilst it moreover exemplifies, by the form and 

 style of the composition, the mode of treatment pursued in 

 the selection of the results obtained from experimental know- 

 ledge. The two succeeding volumes will contain a consi- 

 deration of the particular means of incitement towards the 



