RECORDS. 489 



Members Proposed. 



The following nominations were read and referred to the 

 Council : 



Fred W. Franklin, 700 West End avenue. 

 John I. D. Bristol, i Madison avenue. 

 Rudolph Keppler, 28 West 70th street. 



Academy adjourned. 



Richard E. Dodge, 



Secretary. 



SECTION OF GEOLOGY AND MINERALOGY. 



November 21, 1898. 



Section met at 8 P. M., the Chairman, Professor Kemp pre- 

 siding. Minutes of last meeting were read and approved. 



The first paper of the evening was by Dr. J. H. Pratt, State 

 Mineralogist of North Carolina, on the Occurrenxe, Origin 

 AND Chemical Composition of Chromite. An abstract follows. 



Chromite has only been found in the peridotites and allied 

 basic magnesian rocks and in the alteration products of these 

 rocks. The mineral occurs in grains or crystals and in im- 

 bedded masses near the boundary of lenticular masses of peri- 

 dotite that have been shown to be of igneous origin. The 

 chromite occurs in the fresh as well as in the altered peridotite. 



The theory advanced by the author for the origin of the 

 chromite is that the mineral was held in solution by the molten 

 mass of peridotite and crystallized out from the molten magma 

 as this began to cool. 



The fused mass of rock would hold the different minerals in 

 solution, and as this began to cool, the minerals would separate 

 out, not according to their fusibility but according to their solu- 

 bility in the fused magma. The more basic minerals being the 

 more insoluble would be the first to separate out and in the 

 present case would be the minerals chromite, spinel and corun- 

 dum. This crystallizing or solidifying out from the molten 

 magma would take place first on its outer boundaries, for here 



