134 Prof. How on the Mineralogy of Nova Scotia. 



established by analyses, for gyrolite, and that in the books, 

 which is amply supported by experiment, for okenite, we have, 

 when they are written on both systems of notation, the foU 

 lowing : — 



Old notation. New notation. 



Okenite . Ca Si 2 + H 2 

 CentrallassiteCa 2 Si 3 + H 2 

 Gyrolite . Ca 2 Si 3 + H 3 



Ca Si 2 0,.2H 2 = Ca0.2Si0 2 .2H 2 0. 

 Ca 2 Si 3 8 .2H 2 = 2Ca0.3Si0 2 .2H 2 0. 

 Ca 2 Si 3 8 .3H 2 = 2Ca0.3Si0 2 .3H 2 0. 



wlii eh show very simple relations. These minerals are all 

 somewhat rare natives of trap-rocks ; and the associations of tlio 

 last appear to be much more numerous than those of the others. 

 I have shown that besides occurring with the minerals men- 

 tioned by Anderson, various well-known zeolites at Skye, it is 

 found in this province on the Bay of Fundy associated with 

 calcite and apophvllite, and also with Mordenite ("A new 

 Mineral from the Trap of Nova Scotia," Journal of the Che- 

 mical Society, II. vol. ii. p. 100). 



Stilbite. — It is curious that, abundant as stilbite is in this 

 region, where it exhibits a large number of crystallized varie- 

 ties, some of which are of great beauty, the Nova-Scotian mi- 

 neral has not afforded a single analysis to the treatises on mine- 

 ralogy. Among the most marked varieties may be specified 

 honey-yellow sheaves at Partridge Island, radiated hemispheres 

 at Margaretville and Hall's Harbour, groups of long colourless 

 flattened crystals at the latter place, brownish flattened crystals 

 attached by edges into groups, of which I have procured 

 masses of considerable size from veins some inches thick at 

 Morden, and large brown sheaves with contracted bases set 

 together obliquely, forming curious specimens, at some of the 

 noted localities. " It is also found forming solid homogeneous 

 masses of lamellar structure in thin veins. I analyzed such a 

 specimen, milk-white, translucent in strong light, retaining 

 considerable lustre on cleavage, from the trap on the shores of 

 Annapolis County, near Margaretville or Port George, with 

 these results : — 





Found. 



Calculated. 



Water 



. 16-52 



17-20 



Alumina . 



. 17-28 



16-50 



Lime . . 



. 7-57 



8-90 



Soda . . 



. 2-10 





Silica . . 



. 57-32 



57-40 



100-79 100-00 



It follows, on comparison with the adjacent calculated per- 



