o6 



Cincinnati Society of Natural History. 



rocks terminating in granite whose real method of origin is as yet 

 not definitely settled. 



Foque and Levy conclude that if the origin of granite was known 

 the classification of rocks could be established on a natural basis, since 

 the mode of formation and bulk composition would be known, 

 together with the mineralogical association and structure. 



In the meantime such a classification must be based on those 

 points which we are able to discover. 



LITERATURE. 



A list of the leading works on this interesting subject is here 

 appended. Those who may wish to pursue the discussion further 

 will find complete literature references given in the books. While 

 these two papers are based on the descriptions given in the different 

 books cited below, especial use was made of the work of Foque and 

 Levy which gives a concise treatment of the whole subject : 



Fuchs — Die Kiinstlichen Mineralien, 1870. 



Daubree — Etudes synthetiques de geologie experimentale, 

 Paris, 1879. 



Foque et M. Levy — Synthese des mineraux et des roches, 

 Paris, 1882. 



Bourgeois — Reproduction artificielle des mineraux, Paris, 1884. 

 Doelter — Chemische Mineralogie, pp. 107-172, Leipzig, 1890. 

 Meunier — Les Methodes des syntheses mineraux, 1892. 



[Washburn College, Topeka, Kansas.] 



