PRELUDE TO THE EPOCH OF HAUY. 219 



eyes upon this sinter covered with galena; and thus 

 it constantly happens, that one must have more 

 pleasure in what seems worthless rubbish, than in 

 the purest and most precious ores, if we know aught 

 of minerals." 



Still, however, Henckel 10 disclaims the intention 

 of arranging minerals according to their mathema- 

 tical forms; and this, which may be considered as 

 the first decided step in the formation of crystal- 

 lographic mineralogy, appears to have been first 

 attempted by Linnaeus. In this attempt, however, 

 he was by no means happy; nor does he himself 

 appear to have been satisfied. He begins his pre- 

 face by saying, "Lithology is not what I plume 

 myself upon." (Lithologia mihi cristas non eriget.} 

 Though his sagacity, as a natural historian, led him 

 to see that crystalline form was one of the most 

 definite, and therefore most important, characters 

 of minerals, he failed in profiting by this thought, 

 because, in applying it, he did not employ the light 

 of geometry, but was regulated by what appeared 

 to him resemblances, arbitrarily selected, and often 

 delusive 11 . Thus he derived the form of pyrites 

 from that of vitriol 12 ; and brought together alum 

 and diamond on account of their common octohe- 

 dral form. But he had the great merit of animating 

 to this study one to whom, more perhaps than to 

 any other person, it owes its subsequent progress ; 

 I mean Rome de Lisle. "Instructed," this writer 

 10 p. 167. " Marx. Gesch. p. 97- 12 Sgst. Nat. vi. p. 220. ' 



