WOLFF: LEUCITE-TINGUAITE FROM BEEMERVILLE, N. J. 277 
other combination with ferric iron than as aegirine ; the present case 
indicates some combination with ferrous iron as yet unknown, and of 
course purely hypothetical. 
A rough quantitative mineral calculation of the rock gives : 
Pyroxene, 22 per cent. 
Nepheline, 36 per cent. 
Orthoclase, 38 per cent. 
Titanite, Apatite, etc., 4 per cent. ; 
the analcite actually present is excluded but would of course lower the 
percent of nepheline. Analyses D and E are introduced as the only 
published ones of the elaeolite syenite of Beemerville ; the incomplete 
analysis E shows much similarity with the tinguaite. Analyses F and 
G of leucite-tinguaites differ mineralogically from the Beemerville tin- 
guaite by containing sodalite. 
It should be mentioned that J. F. Kemp (loc. cit.) has described two 
camptonitic dikes — six, and nine and a half miles respectively distant 
from the Beemerville dike — in which certain curious spheroids without 
definite crystal outlines and composed mainly of analcite are referred to 
original leucite, of which some traces are stated to remain. 
MINERALOGICAL LABORATORY, 
HarvarpD UNIVERsITY, Jan., 1902. 
