l v j INTRODUCTION. 



fallen into the grossest errors concerning ophite, &c. because 

 they neglected to consult the original passages ? 



Apology for In the present work, it is hoped that the want of attention, 

 this work. c&r ^ Qr j^^ w ju no t be accused. The author has sedu- 

 lously employed the intervals of ten years in this production, 

 particularly three which he passed at Paris, where he had 

 constant opportunities of seeing the most opulent cabinets, 

 and of conversing with men eminent in the science, as 

 Patrin, Gillet Laumont, Daubuisson, and others ; not to men- 

 tion interviews with Haiiy, and with Werner during his short 

 stay in that capital. It was resumed at intervals of other 

 studies, the change of labour being itself an amusement. 

 He hopes the work may at least aspire to the humble praise 

 of utility, the chief aim of his labours : terar dum prosim. 

 In the preface to his grand treasure of ancient knowledge, 

 Pliny has observed that it is laudable to mention the authors 

 by whose works you profit. Not contented with exact refer- 

 ences, the author has often adduced the original passages, 

 not only for the sake of greater accuracy, but to save the 

 reader the trouble and expense of consulting many works, 

 which perhaps contain only a few pages on this particular 

 subject, which has hitherto been treated as a mere appendage 

 to mineralogy. There are also numerous extracts of great 

 value, from works in foreign languages, of which, from 

 their nature, the English reader can scarcely ever expect to 

 see complete translations. These extracts will, it is hoped, 

 from the variety of the style, throw some flowers over a sub- 

 ject proverbially barren 5 while the expressions of the ob- 

 servers themselves, in the sensations arising from grand phe- 

 nomena, sometimes enliven the subject with somewhat of a 

 dramatic interest. It must also be remembered, that mosaic 

 is even more difficult than painting, and of incomparably 

 longer duration. Some regard it as a maxim in literature, 

 that a book should be as complete in itself as possible ; and a 

 reference to a work, which he can neither procure nor read, 

 would cont rib ute little to the instruction of the learner. The 

 candid will likewise consider the entire novelty of the plan > 



