SECTION I. 

 GENERAL VIEW. 



THE regularity and symmetry observable in the 

 forms of crystallized bodies, must have early attracted 

 the notice of naturalists ; but they do not appear to 

 have become objects of scientific research, as a branch 

 of natural history, until the time of Linnaeus. He 

 first gave drawings and descriptions of crystals, and 

 attempted to construct a theory concerning them, 

 somewhat analogous to his system of Botany. 



We are indebted however to Rome de L'Isle for 

 the first rudiments of crystallography. He classed 

 together those crystals which bore some common 

 resemblance, and selected from each class some sim- 

 ple form as the primary, or fundamental one ; and 

 conceiving this to be truncated in different directions, 

 he deduced from it all its secondary forms ; and it 

 was he who first distinguished the different species 

 of minerals from each other by the measurements of 

 their primary forms. 



The enquiries of Bergman were nearly contem- 

 poraneous with those of the Abbe Haiiy, and both 

 these philosophers appear to have entertained at the 

 same time nearly the same views with regard to the 

 structure of crystals ; both having supposed that 

 the production of secondary forms might be explained 

 by the theory of decrements on the edges or angles of 

 the primary. 



E 



