OF NATURAL PHILOSOPHY. 259 



that no natural phenomenon can be adequately 

 studied in itself alone, but, to be understood, must 

 be considered as it stands connected with all nature. 



(287.) The new class of phenomena thus disclosed 

 were immediately studied with diligence and suc- 

 cess, both abroad by Malus and Arago, and at 

 home by our countryman Dr. Brewster, and their 

 laws investigated with a care proportioned to their 

 importance ; when another and apparently still more 

 extraordinary class of phenomena presented itself 

 in the production of the most vivid and beautiful 

 colours (every way resembling those observed by 

 Newton in thin films of air or liquids, only infinitely 

 more developed and striking,) in certain transparent 

 crystallized substances, when divided into flat plates 

 in particular directions, and exposed in a beam of 

 polarized light. The attentive examination of these 

 colours by Wollaston, Biot, and Arago, but more 

 especially by Brewster, speedily led to the disclosure 

 of a series of optical phenomena so various, so 

 brilliant, and evidently so closely connected with the 

 most important points relating to the intimate struc- 

 ture of crystallized bodies, as to excite the highest 

 interest, that sort of interest which is raised when 

 we feel we are on the eve of some extraordinary 

 discovery, and expect every moment that some lead- 

 ing fact will turn up, which will throw light on all 

 that appears obscure, and reduce into order all that 

 seems anomalous. 



(288.) This expectation was not disappointed. 

 So long before the time we are speaking of as the 

 first year of the present century, our illustrious 

 s 2 



