Prof. How on the Mineralogy of Nova Scotia. 137 



two samples from veins in the North Mountain of Annapolis 

 Co., known as Romans and Tremain ore, which resembled such 

 compact ore as I have seen from other parts of this trap-region, 

 with the following results : — 



Romans. Tremain. 



Quartz 5-46 4-94* 



Magnesia and traces 



of lime 1-27 4*84 



2S£ & defi ? iency ?i||| } »™ ill } •■>». 



100-00 100-00 



On calculating the metallic iron to magnetic oxide, there is 

 per cent, for Romans 94*36, and for Tremain 89*80, which 

 amount agrees so closely with the weight of the iron found 

 added to the oxygen by loss in each case as to show that the 

 minerals are nearly true magnetic oxide in the ratio of 

 FeO : Fe 2 3 ; the replacement by magnesia, so common in the 

 species, is unequal. 



Magnetic Haematite. — The trap of Digby Neck also affords 

 micaceous iron-ore in small crystals disseminated in the rock 

 and in cacholong, with agate and quartz, near St Mary's Bay, 

 and at the same place, Johnson's, haematite in large modified 

 crystals in numerous veins, some of which are 5 inches thick. 

 A few miles east of this locality haematite is found beautifully 

 crystallized in forms apparently showing its derivation from 

 magnetite. At both places the crystallized mineral has the 

 red streak of haematite, while a good deal, if not all, is more or 

 less magnetic to the needle. The experiments of Hausmann, 

 Henrici, H. Rose, and others show that the magnetism of 

 haematite does not arise from a mixture of protoxide of iron, 

 as is often asserted (for the pure peroxide can acquire mag- 

 netism in a high degree), but depends chiefly on the state of 

 aggregation, the more crystalline and compact varieties being 

 also the more highly "magnetic (Nicol's *" Mineralogy,' p. 398). 



Antimony. — In the course of analysis of trap rock from 

 Margaretville my son and pupil, Mr. H. How, found decided 

 traces of antimony ; in what form it exists is not made out. 

 This metal has not been certainly found, except with galena 

 and to a very small amount, in this province ; but it exists as 

 sulphide in the adjoining province of New Brunswick, but not 

 on the bay-shore opposite Margaretville ; and it occurs iii a 

 geological formation very unlike the Triassic trap of Nova 

 Scotia. 



* With traces of titanium. 



Phil Mag. S. 5. Vol. 1. No. 2. Feb. 1876. L 



