117 
On Gyrolite occurring with Calcite in Apophyllite in the 
Trap of the Bay of Fundy. By Henry How, Professor of 
Chemistry, &c., King’s College, Windsor, Nova Scotia. 
The mineral gyrolite was first described by Professor Anderson 
of Glasgow,* as a new species from the Isle of Skye; it is stated by 
Greg and Lettsom} to occur without doubt at two localities in Green- 
land, and according to Heddle at Farée. The only other notice of 
it that I am acquainted with is by L. Seemann, who mentions{ that 
he examined a specimen—no locality being given—mixed or inter- 
laminated with pectolite, and suggests that this mineral, losing its 
alkali, becomes gyrolite, and, losing its lime, becomes okenite. No 
other analysis than the original one of Professor Anderson has, I 
believe, been published; the following account of its occurrence 
among the minerals of Nova Scotia shows it in such associations as 
affords a mode of explaining its origin by change in apophyllite. 
I met with it in Annapolis Co., N.S., some 25 miles S.W. of 
Cape Blomida, between Margaretville and Port George, on the sur- 
face of fractured crystalline apophyllite, and, on further breaking 
the mass, a good many spherical concretions of pearly lustrous plates 
were observed in the interior, of sizes varying from that of a pin’s 
head to nearly half-an-inch in diameter; their outline was well 
defined, and the external characters, as given by Anderson, were 
recognised on examination; it afforded the following results on 
analysis :—The mineral was ignited for water, and the residue 
treated with hydrochloric acid, the resulting dried silica was weighed, 
and then fused with carbonated alkali, and the weight of the small 
quantities of alumina, &c., so separated, was deducted from that of the 
first silica, I place my numbers by the side of those of Professor 
Anderson, and give the calculated percentages for his formula :— 
H. H. Anderson. 
Potass,. . 1°60 
Magnesia, . 0°08 0°18 Calculation. 
Alumina, . 1:27 148 00 ———_______ 
Dime, +. 29:95 33°24 32°26 2CaO =56 
mes. 1. 51°90 50°70 52.18 2810, = 90°6 
Water, . . 15°05 14°18 15°35 o Oe eg, 
Cee ny 
——___, 
99°85 99°78 99°99 173°6 
_ * Trans. Roy. Soc. Edin., and Phil. Mag. Feb. 1851. 
~ Manual of Mineralogy, p. 217. 
{ First Supp. to Dana’s Mineralogy, p. 9; Silliman, May 1855. 
