OF CEVTRAL CANADA PART II. 67 



APPENDIX TO GROUP I. 



10. Meteoric Iron: Dark steel-grey; malleable; strongly magnetic; 

 H = 4.5 ; sp. gr. about 7.4 ; fracture, hackly. BB, infusible. 



An irregular mass of malleable iron weighing about 750 Ibs. was 

 discovered in 1854, on the surface of the ground, in the Township of 

 Madoc. Its examination by Dr. Sterry Hunt showed the presence of 

 6.35 per cent of Nickel, with other characters belonging to ordinary 

 examples of meteoric iron. It exhibits a dark coating of oxide, and 

 contains a small amount of intermixed phosphide of iron (Schreiber- 

 site) and magnetic pyrites. Nitric acid brings out on the polished 

 surface the so-called Widmannstadt's figures, or intersecting lines and 

 zigzag markings indicative of an irregular crystalline structure. 



II. ARSENIDES AND SULPHIDES. 



[This sub-division contains the various compounds of arsenic and 

 sulphur with metallic bases, hitherto found in Central Canada. These 

 may be conveniently described under five groups, as follows : Sul- 

 phides of Silver, Lead, and Zinc ; Sulphides of Copper ; Arsenides 

 and Sulphides of Nickel and Iron ; Sulphide of Molybdenum ; and 

 Sulphides of Bismuth and Antimony.] 



A. SULPHIDES OF SILVER, LEAD, AND ZINC. 



11. Silver Glance or Argentite : Black, or dark lead-grey; malle- 

 able ; Regular in crystallization, but occurring commonly in small 

 irregular masses, or in leafy or delicate arborescent forms. H = 2.0 

 2.5 ; sp. gr. 7.2 7.4. BB, melts with bubbling, and yields a 

 globule of metallic silver. 100 parts contain normally : Sulphur 12.90, 

 Rilver 87. 10. Hitherto, only found ^ith native silver, &c., at Prince's 

 Location, Lake Superior, and in the silver veins of Thunder Bay. 

 At the " Withers Mine/' at a depth of nearly sixty feet from the sur- 

 face, several crystals, combinations of cube and octahedron, measuring 

 the fourth of an inch across, were obtained by the writer ; and some 

 others of still larger size were found in the same shaft by Mr. Mc- 

 Intyre of Fort William, One of these (sp. gr. 7.31) yielded : sulphur 

 13.37 ; silver 86.44 ; copper, slight trace. The adjacent mine of the 

 Thunder Bay Company has also furnished some good specimens. 



12. Galena: Lead-grey; more or less sectile, but not malleable ; 

 Regular in crystallization, and often met with in cubes (fig. 36) 



