HO DISCOURSE ON THE STUDY 



to take root ; and every new writer on this inter- 

 esting science begins, as a matter of course, by 

 making a tabula rasa of all former nomenclature, 

 and proposing a new one in its place. The climax 

 has at length been put to this most inconvenient 

 and bewildering state of things by the appearance 

 of a system supported by extraordinary merit in 

 other respects, and therefore carrying the highest 

 authority, in which names which had acquired 

 universal circulation, and had hitherto maintained 

 their ground in the midst of the general confusion, 

 and even worked their way into common language, 

 as denotive of species too definite to admit of mis- 

 take, are actually rendered generic, and extended to 

 whole groups, comprising objects agreeing in nothing 

 but the arbitrary heads of a classification from which 

 the most important natural relations are professedly 

 and purposely rejected.* 



(134.) The classifications by which science is ad- 

 vanced, however, are widely different from those 

 which serve as bases for artificial systems of nomen- 

 clature. They cross and intersect one another, as it 

 were, in every possible way, and have for their very 

 aim to interweave all the objects of nature in a close 

 and compact web of mutual relations and dependence. 

 As soon, then, as any resemblance or analogy, any 

 point of agreement whatever, is perceived between 

 any two or more things, be they what they will, 

 whether objects, or phenomena, or laws, they im- 



* In the system alluded to, the name of quartz is assigned 

 to iolite and obsidian ; that of mica to plumbago, chlorite, and 

 uranite ; sulphur, to orpiment and realgar, &c. See Mohs's 

 System of Mineralogy, translated by Haidinger. 



