PREFACE. 



THE present volume, which is designed to take a systematic, but popular, 

 survey of the most interesting features of the general SCIENCE OF NATURE, 

 for the purpose of elucidating what has been found obscure, controverting 

 and correcting what has been felt erroneous, and developing, by new and 

 original views and hypotheses, much of what yet remains to be more satis- 

 factorily explained, derives its origin from the following circumstances : 



Towards the close of the year 1810, the author had the honour of 

 receiving a visit from a deputation of the Directors of the SURREY INSTI- 

 TUTION, founded on what had been antecedently the LEVERIAN MUSEUM, 

 with a request on the part of their Chairman, Dr. Adam Clarke, that he 

 would undertake a department of lectures in that literary and scientific 

 establishment ; with the generous offer of leaving to himself a nomination 

 of time, terms, and subject. He regretted his inability of acceding to so 

 kind a request at that particular period ; but being a little more at liberty 

 not long afterward, he readily consented, on a second application by 

 Dr. Lettsom and other Directors ; and the ensuing volume contains the 

 course of study he ventured to make choice of; the lectures having been 

 divided into series, and delivered in successive years. 



It was his intention to have carried the plan to a somewhat more pro- 

 tracted extent, though the present is sufficiently complete for the outline 

 laid down ; but, though earnestly and repeatedly pressed to proceed farther, 

 or even to go over the same lectures again, an augmented sphere of pro- 

 fessional duties compelled him, with much reluctance, to decline the invita- 

 tion ; and the same cause has prevented him," till the present period, from 

 fulfilling a subsequent request to submit them to the public ; though he has 

 always intended to do so as soon as he could find leisure. 



As the lectures were delivered from general recollection, though with 

 the author's manuscript at hand, it is possible that those who took notes 

 may find a few passages in the pressi text slightly varied from what was 



