182^ J Scientific ItioticeS'-^Mineralogy, 391 



produced. Whether touched by metal, glass, wood, or the skin, 

 the change seemed equally rapid; but it appeared to require 

 actual contact ; no vibration of the glass on which the globules 

 lay rendered them solid, and many of them were retained for a 

 week in their fluid state. This state of the sulphur appears 

 evidently to be analogous to that of water cooled in a quiescent 

 state below its freezing point ; and the same property is also 

 exhibited by some other bodies, but I believe no instance is 

 known where the difference between the usual point of fluidity 

 and that which could thus be obtained is so great : it, in the 

 present instance, amounts to 130°, and it might probably have 

 been rendered greater if artificial cold had been applied. — 

 (Journal of Science.) 



5. Detection of Arsenic. 



The following " elegant test of the precise nature of the 

 metallic crust (viz. that obtained by Dr. Christison's method of 

 detecting arsenic) when its quantity is too minute for its physi- 

 cal characters to be unequivocally ascertained, was communi- 

 cated to Dr. Christison by Dr. Turner, Lecturer on Chemistry in 

 Edinburgh. It consists in chasing the crust up and down the 

 tube by heat till it is all oxidated ; when it assumes the appear- 

 ance of sparkling crystals, which may he ascertained by a micro- 

 scope of four powers to he octohedraJ' — (Extract from Edin. 

 New Phil. Journ.) 



Mineralogy. 



6. Analysis of TIalloyite, 



This mineral has been analysed by M. Berthier, it is found at 

 Angleure, near Liege ; it occurs in kidney form, or tubercular 

 masses larger than the fist, among the ores of iron, zinc, and 

 lead, which occupy the cavities of the transition limestone of 

 the north, and which are especially so common in the provinces 

 of Liege and Namur. M. Omalius d'Halloy is the first who 

 noticed it some years since ; mineralogists will therefore un- 

 doubtedly approve the name given to this substance, as that of 

 a philosopher who has so greatly contributed to the study of 

 geology. .... 



Halioylite is compact, its fracture is the waxy conchoidal ; 

 it may be indented by the nail and polished by rubbing with 

 the finger ; its colour is pure white or white slightly shaded 

 with greyish blue; it is transparent at the edges, and adheres 

 strongly to the tongue. When small pieces are put into water 

 it becomes transparent like hydrophane ; air is given out, and 

 its weight is increased about one-fifth. By calcination it loses 

 0*265 to 0*280 of water, becomes very hard and milk white. 



If it be powdered and exposed for some time to a temperature 

 of nearly 212°, it loses water, for after that it does not lose morsv 



