THE HAUIAN CRYSTALLOGRAPHY. 233 



added, in this way, to the stock of knowledge, would 

 be superfluous. 



Nor need I dwell long on those who added^to 

 the knowledge which Haiiy left, of derived forms. 

 The most remarkable work of this kind was that of 

 Count Bournon, who published a work on a single 

 mineral (calcspar) in three quarto volumes 2 . He 

 has here given representations of seven hundred 

 forms of crystals, of which, however, only fifty-six 

 are essentially different. From this example the 

 reader may judge what a length of time, and what 

 a number of observers and calculators, were re- 

 quisite. to exhaust the subject. 



If the calculations, thus occasioned, had been 

 conducted upon the basis of Haiiy's system, without 

 any further generalization, they would have belonged 

 to that process, the natural sequel of inductive dis- 

 coveries, which we call deduction ; and would have 

 needed only a very brief notice here. But some 

 additional steps were made in the upward road to 

 scientific truth, and of these we must now give an 

 account. 



2 Traite complet de la Chaux Carbonatee et d'Aragonite, par 

 M. le Comte de Bournon. London, 1808. 



