﻿On a New Alkali Hornblende. 77' 



[Additional facts and illustrations, and references tO' 

 previous papers on the subject, will be found in " Speci- 

 mens of Eozoon Canadense," pp. 106, published by. the 

 Peter Eedpath Museum (Notes on Specimens, Sept. 1888),. 

 which may be obtained on application to the Museum, or 

 through W. Foster Brown, Bookseller, Montreal. See,, 

 also, for a popular summary. Chapters V. and VI. of 

 " Some Salient Points in the Science of the Earth," Lon- 

 don, 1893.] 



On a New Alkali Hornblende and a Titaniferous 

 Andradite from the Nepheline- Syenite of Dun- 

 GANNON, Hastings County, Ontario. ^ 



By Frank D. Adams and B. J. Harrington, 

 McGill College, Montreal. 



In a paper which appeared in the American Journal of 

 Science for July, 1894, the discovery of a large area of 

 nepheline syenite in the township of Dungannon, in the 

 Province of Ontario, was announced and the geological 

 relations and mineralogical characters of the mass briefly 

 described. 



One of the many peculiarities of this rock is the- 

 absence from it of the mineral pyroxene, which is usually 

 the chief iron-magnesia constituent in rocks of this class,, 

 its place being taken by hornblende and mica, but even 

 these minerals are present in comparatively small 

 amount. Of the hornblende two varieties, occurring in. 

 different parts of the mass, were distinguished. The- 

 first, from near the York river, has a large axial angle- 

 with strong pleochroism in tints varying from pale yellow 

 to deep green, and although containing a considerable- 

 amount of soda, probably approaches common green horn- 



1 [Reprinted from the American Journal of Science, March,, 1896.] 



