152^ Miscellaneous Intelligence, 



heated onplatina foil by a spirit-lamp, tinged the flame of an azure 

 blue colour. A portion heated in a glass tube, gave off at first 

 acidulous water, then some sulphur, afterwards a yellow vapour, 

 condensing into a red sublimate, arose, and the residuum, by being 

 heated in a tube open at both ends, left a grey earthy substance, 

 principally silica and lime, amounting to about 53 per cent, of the 

 weight of the original substance ; consequently, there was about 

 47 of volatile matter, of which by far the largest portion was the 

 red sublimate. It had fused and spread over the inner surface of 

 the tube. A portion of it gave the same blue colour to flame before- 

 mentioned, but more intense. Another portion, in an open tube, 

 sublimed without giving off any sulphur, exhaling a strong odour 

 like that of horseradish. It fused when heated gently, remaining 

 awhile in a pasty state. It has a metallic lustre, a deep brown 

 colour by reflected light; conchoidal fracture with a vitreous 

 lustre ; easily scratched by a knife ; brittle ; powder deep red ; ad- 

 hering when rubbed in a mortar, having then a grey, smooth, and 

 somewhat metallic lustre. When in very thin lamina it is trans- 

 parent, being of a beautiful cinnabar red colour. 



8. Alloy of Antimony and Potassium, first ^produced by Geoffroy. 

 — ^M. SeruUas observed, amongst numerous other facts, on the pro- 

 duction of alloys of antimony and potassium, that if emetic tartar 

 be heated to whiteness in a covered crucible for two or three hours, 

 there will be obtained, when cold, a carbonaceous mass which in- 

 flames spontaneously on exposure to the atmosphere. M. Serullas 

 states, that this pyrophoric property of antimony, heated with 

 carbon and potash, was pointed out by Klaproth, who, without 

 knowing the cause, had observed the effect ; but M. Derheins has 

 more lately shewn, that the same property had been observed by 

 Geoffroy, in 1736, and described by him at length, in VHistoire de 

 r Academic, ^c, for that year. He calls it a new detonating phos- 

 phorus made with antimony. It was obtained by mixing one ounce 

 of diaphoritic antimony with two ounces of black soap, putting the 

 mixture by degrees into a hot crucible, ultimately adding another 

 ounce of soap, covering up the vessel and heating it violently, it 

 was left to cool. In the evening when opened, it suddenly took 

 fire by contact of air, and burnt with explosion ; there were no 

 fluid scoria, but the whole had formed a spongy mass. The process 

 was repeated several times and always with the same result.— 

 Journ. de Phar. 1824. p. 631. 



9. Composition of Crystals of Sidphate of Soda. — It is known 

 that when a hot strong solution of sulphate of soda is put into a 

 vessel and closed up, it may be reduced to common temperatures 

 without crystallizing, although, if the vessel be opened, abundance 

 of crybtals will immediately form. It has also frequently been 



