Sect. III.] Mineralogy. 1 97 



constUuent parts of a crystal. lu tlils manner 

 Bergman developed the meelianical .strncture of. 

 vai'ious crystals, and showed thnt the primitive 

 form often lies coneealed in those wvy erystak 

 which appear to deviate fartliest from it. 



AI. Hauy pursued the idea, and applied it to 

 various crystallised minerah:. II(; is supposed to 

 have shown, not only that every particular species 

 of crystal has a primitive figure, and that the varia- 

 tions axe owing to the dilferent ways in which the 

 pai'ticles am^ai^ge themselves ; but also to ha\ e de- 

 termined the laws according to which the decre- 

 ments take place, after certain data which he as^. 

 sumed. His theory of crystallisation has been 

 much celebrated. It is generally considered as iur 

 genious and plausible ; and certainly manifests a. 

 degree of diligence, zeal, and mathematical skill, 

 which entitle him to much connncndation ^. 



In addition to the great systematic writers 

 whose names have been mentioned, considerable 

 service has been rendered to mineralogy, within 

 the period under consideration, by many others, 

 who have either collected, analysed, or discovered, 

 mineral productions. Among these it is proper 

 to enumerate, with some distinction, Lawson, 

 Townson, Jamison, Whitehurst, Lewis, Anderson, 

 Withering, and Garnet, of Great Britain; d'Argcn- 

 ville, Soulavie, Faujas, Macquart, Dolomieu, Mou- 

 net, Chaptal, Bomare, Fourrroy, Ihissenfratz, and 

 de la Metherie, of France; Ludwig, AVoltersdorlf, 

 Cai'theuser, baron Born, Debern, A'oii^t, Gellert, 

 Woulfe, Raspe, and many more, of Ciurmany ; de 



'^ See Tilloch's Philosophical Mas'izinc, and Nicliolsou's Jounutl. 



