876 On Metallic Minerals. 



han, who has had better opportunities of judging, is of 

 opinion that it is still abundant. As it was necessary to 

 transport this ore to the works by land, having first 

 extracted it from a tough sienite, the bed has been aban- 

 doned in favor of the ore on the Marmora Lake. Much of 

 this ore is mixed up with calcareous spar, which, of course 

 acts as a flux and assists its fusion, on this account it 

 is sometimes used in the operations of the furnace to 

 produce a hotter cinder. 



It contains sulphur, but apparently not so much as the 

 last bed. Its geological relations are the same, that is to 

 say, sienitic, but it differs mineralogically in containing, 

 besides calcareous spar, octohedral chrystals of iron and 

 garnet. Dr. Bigsby, I believe, says manganesian garnet, 

 but using a flux of borax and nitre, I never could develope 

 before the blow-pipe the amethystine tint so characteristic 

 of the presense of manganese, when in any quantity ; the 

 colour of the globule was always green or yellow, like that 

 produced by iron alone. Garnet also occurs here in amor- 

 phous masses, and may be considered an ore of iron, 

 although, a poor one; it is, however, very easily fusible and 

 valuable on that account as a flux. 



MIXERALOGICAL CHARACTERS. 



Several of the ores from this bed, so neai-ly resemble some 

 of those Avhich have been described as occurring in the 

 main deposit on the Marmora Lake, that it is superfluous 

 to describe them, I shall confine myself therefore to those 

 which appear to differ. 



1st. — Colour, steel grey ; opaque ; structure, laminar, 

 the mass having a tendency to break into fragments of a 

 rhomboidal shape, with smooth sides ; cross fracture, 

 uneven; lustre, shining, (almost splendent) ; rcsino metallic. 



