portion of the 
364 O. C. Marsh on Ledererite from Nova Scotia. 
the prisms were marked with horizontal strise, while the planes 
of the pyramids were striated parallel to their polar . 
These striee were in most instances much more distinct than 
those seen occasionally on crystals of Gmelinite from Irish lo- 
calities, or from Iceland. There was, moreover, in most of the 
specimens a tendency toward a rhombohedral form, as seen 
in the much greater prominence of alternate pyramidal planes, 
a peculiarity rarely observed hitherto in Gmelinite. In seve 
of the crystals this resulted in the form given in fig. 2. 
2. 
As the amount of the mineral obtained was sufficient for 
chemical examination, the writer, while a student at Heidelberg 
in 1863, made two analyses of it in the laboratory, and | 
the direction of Prof. Bunsen. | 
An attempt was first made to decompose the finely powdered 
mineral with hydrochloric acid, but without success, pete" 
to say, the mineral was apparently little affected. 
ing to Brunner’s methc 8, 
in analysis No. 16, separated in the usual manner. A t of 
: eral was first used fora determinatio? 
