Piso AOllLONs 
OF THE 
Nova Scotian Fustitute of Batuval Seience. 
Art. I—NoTES ON A POLARISCOPIC EXAMINATION OF CRYS- 
TALLINE Rocks OF THE YARMOUTH GOLD-BEARING 
SerRrES.—By Pror. HonryMAN, D.C.L., &c. Curator 
of the Provincial Museum. 
(Read Nov. 13, 1882.) 
THE problematical character of those rocks, and their unex- 
pected appearance in the gold bearing series—no similar rocks 
appearing elsewhere in the band, as far as observed,—led me to 
have sections prepared by A. A. JuLIEN, New York, for micro- 
scopic and polariscopic examination. 
1,2. The rock at Jeboque Point has suggested a number 
of queries. (Vide Paper on “ Geology of Digby and Yarmouth 
Counties.” Trans. 1880.) Its appearance and relations suggested 
a comparison with the Igneous rocks of the Blomidon seties. [ 
had also a section made of Blomidon Basalt. The two examined 
by the polariscope are so much alike as to be regarded identical. 
The dark material of both is evidently Augite, and the clear 
erystals a triclinic feldspar. The latter polarized shew three 
parallel lines. Between two parallels the colour is a beau- 
tiful blue-white, the colour between the other two is dusky. 
Turning the polarizer the colours change place——the dusky 
becoming blue, and the blue dusky. This seems to furnish a 
reply to my queries, and to refer the eruption at Jebogue Point 
to the Paulo-post Triassic Period. ’ 
3, Sunday Point Porphyrite.—A macroscopic examination 
