318 HISTORY OF MINERALOGY. 



he speaks 9 with entire decision on this subject : " Nevertheless since 

 there is here a principle of crystallization, the inclination of the planes 

 and of the angles is always constant." He even anticipates, very 

 nearly, the views of later crystallographers as to the mode in which 

 crystals are formed from elementary molecules. From this time, many 

 persons labored and speculated on this subject ; as Cappeller, whose 

 Prodromus Crystallographies appeared at Lucern in 1723 ; Bourguet, 

 who published Lettres Philosophiques sur la Formation de Sels et de 

 Cristaux, at Amsterdam, in 1792 ; and Henckel, the "Physicus" of 

 the Elector of Saxony, whose Pyritologia came forth in 1725. In this 

 last work we have an example of the description of the various forms 

 of special classes of minerals, (iron pyrites, copper pyrites, and arsenic 

 pyrites ;) and an example of the enthusiasm which this apparently dry 

 andlaborious study can excite: "Neither tongue nor stone," heexclaims, 9 

 " can express the satisfaction which I received on setting 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 mine- 

 rals according to their mathematical forms ; and this, which may be 

 considered as the first decided step in the formation of cry stalfographic 

 mineralogy, appears to have been first attempted by Linnseus. In this 

 attempt, however, he was by no means happy ; nor does he himself 

 appear to have been satisfied. He be'gins his preface by saying, 

 " Lithology is not what I plume myself upon." (Lithologia, mihi cris- 

 tas 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 geome- 

 try, 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 ; 1J and brought together alum and diamond 

 on account of their common octohedral 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 says, in his preface to his Essais dt 

 Crystallogra'phie, " by the works of the celebrated Von Linnee, how 



* p. 83. 9 p. 343. 10 p. 167. n Marx. Gesch. p. 97 



12 Syst. Nat. vi. p. 220. 



