﻿Prof. How on the Mineralogy of Nova Scotia. 269 



cent, water ; hence there can be no doubt as to the nature of the 

 species. 



Delessite? — There are frequently seen in the araygdaloidal 

 traps of the western part of the province masses of a soft, dark 

 green, chlorite-like mineral ; or perhaps there are more species 

 than one having these characters, sometimes filling rock- cavities 

 more or less completely, and occasionally coating or partly com- 

 posing zeolites, as, for example, analcime, which in different loca- 

 lities has its colour thus made to vary through all shades to dark 

 green. At one place, Two Islands, in the Basin of Minas, I 

 observed, several years ago, large crystals of this species lying 

 loose in a cavity of the trap above high-water mark, like speci- 

 mens on the shelf of a cabinet. I could not get as many of 

 these as I wished, nor examine the nature of the cavity, on account 

 of the rapidly rising tide. Some of the crystals were colourless ; 

 one was most curiously composed: nearly half of the upper por- 

 tion consisted of white partly transparent analcime • the rest, 

 including the whole base, was almost entirely made up of a soft 

 dark-green mineral like chlorite. The crystal had the form of 

 analcime * it was about an inch and a quarter in diameter. I 

 made no analysis of the green mineral in this case; but I examined 

 a specimen of similar soft, green, greasy-looking mineral from 

 cavities of trap on the Bay of Fundy. It was very dark in colour, 

 opaque to the naked eye, translucent under the microscope, very 

 soft, fusible on the edges to a black glassy bead before the blow- 

 pipe. It dissolved partially in slightly warmed hydrochloric 

 acid, to which it gave both protoxide and peroxide of iron in 

 large quantity. Water was lost on ignition and was so estimated ; 

 the amount obtained in this way, however, would be rather below 

 the truth, owing to the absorption of oxygen by the protoxide 

 of iron. Alkalies were not sought for. Analysis of the air- 

 dried mineral gave : — 



Silica 40-53 



Metallic iron .... 12*50 



Alumina 6*95 



Lime . 0*52 



Magnesia 14*15 



Gangue 2*87 



Water (by ignition) . . 13*10 



Oxygen and loss . . . 9*38 



100*00 



These results appear to place the mineral between Delessite 

 and epichlorite, which have the following composition* : — 



Dana's ' Mineralogy,' 5th edit. pp. 493, 49/. 



