66 Explosion in a J'ein of Pyrites. 



portion lieated by the spirit lamp in n glass tube closed at one 

 end gave off first acidulous water ; some sulphur next sub- 

 limed and condensed at a little distance from the flame, and 

 soon after a red substance, which condensed on the sides of the 

 tube between the flame and the sulphur, and very near the 

 former. During the sublimation of the red matter, the lower 

 part of the tube was filled with a yellow vapoin-, a good deal 

 like chlorine, but of a deeper colour, and an mipleasant odour 

 w-as exhaled, very similar to that of cabbage water. Alter the 

 whole of the volatile matter had been sublimed, a fixed dark- 

 coloured residuiun remained at the bottom of the tube. This 

 was transferred to another tube, open at both ends, and again 

 heated ; some more of the red sublimate was thus obtained, and 

 the residuum assumed a grey colour. It amounted to about 

 "53 per cent, of the weight of the substance operated on, and 

 on examination was found to consist of earthy matter, princi- 

 pally silica and lime ; consequently the assay contains about 

 ^V per cent, of volatile matters, by far the greatest portion of 

 which consists of the red sublimate. The red sublimate had 

 evidently been ftised and spread over the inner surface of the 

 tube. 



When detached from the tube, a morsel of it imparted the 

 same beautiful blue colour to flame that has been ah^eady men- 

 tioned, but more intense. 



Another fragment, heated in a tube open at both ends, sub- 

 limed without giving ofi^any sulphur, exhaling at the same time 

 a strong odour similar to that of horse-radish. It fused very 

 readily on being gently heated in a close tube over the lamp, 

 and remained for some time in a soft pasty state. 



These experiments are quite sufiicient to establish the iden- 

 tity of our red sublimate with selenium, and in external cha- 

 racters also it perfectly answers the description of that sub- 

 stance. It has a metallic lustre, and a deep brown colour when 

 seen by reflected light. Its fracture is conchoidal, and has a 

 vitreous lustre. It is easily scratched by the knife, is brittle, 

 and its powder has a deep red colour ; but it adheres toge- 

 ther readily when rubbed in the mortar, and then assumes 

 a grey colour, and a smooth and somewhat metallic sxu'face. In 

 very thin laminae it is transparent, and when viewed by trans- 

 mitted light has a beautiful cinnabar red colour. 



ACCOUNT OF AN EXPLOSION IN A VEIN OF PYRITES. 



This explosion took place, sixteen years ago, in the town- 

 ship of Yonge, near the Lake of the Thousand Isles in the 

 .St. Lawrence. At the time, a man was seeking his cow in the 

 woods, within a short distance of the spot. On a sudden he 



was 



