Chemical Science, 161 



long, and l-20th of an inch in diameter at the base. These may 

 be directed accurately upon the minutest visible particle, and being 

 slightly moistened at the point with saliva, the particle will adhere 

 to the apex under the strongest blast of the blow-pipe. These 

 cones need not be more than one-fourth or one-fifth of an inch in 

 length, for so effectually is the conducting power of the mass in- 

 terfered with by the pulverization of the mineral, that one of them, 

 half an inch in length, may be held in the fingers whilst the apex is 

 in the focus of heat. A great advantage of this method over others 

 is, that if fusion ensues, it is owing entirely to the nature of the 

 substance experimented upon, and not to the agency of foreign 

 substances acting as fluxes. — Ann. Lyceum^ of I)[€w York. 



6. Examination of Fused Charcoal. — At last a specimen of fused 

 charcoal or supposed artificial diamond has been examined. The spe- 

 cimen was obtained by Professor Macneven of New York, by means 

 of Hare's deflagrator, was sent to Dr. Cooper, and by him presented 

 to Mr. Vanuxem, who examined it, having always been very scep- 

 tical on the subject of the fusion of charcoal. It consisted of a 

 large and small globule connected together by a thread, colour 

 black, without lusti-e, opaque. When struck it yielded without 

 breaking, receiving a polish like that of iron ; when filed it gave 

 way as iron or soft steel would do ; it was attracted by the magnet, 

 and when hammered was malleable. Nitric acid, when heated, 

 acted violently on it, and, ultimately, peroxide of iron and a little 

 silica were obtained. The proportion of silex to metallic iron 

 was about 11:5. 



Such, therefore, is the nature of tlie black fused charcoal, and 

 there can be no doubt that the colourless fused charcoal is also 

 due to the impurities of the charcoal acted upon, as was formerly 

 supposed *. — Philadelphia Journal. 



Messrs. Silliman and Hare deny, however, that Mr. Vanuxem 

 has operated on a proper specimen. 



7. Selenium in Anglesea Pyrites.'-^An account is given in the 

 Annals of Philosophy, New Series, ix. 52, of the production of sele- 

 nium, during a process in which sulphuric acid, made from Angle- 

 sea pyrites, is used. The acid is prepared by Mr. Mutrie of Man- 

 chester, and is used by Mr. Thomson, who observed the produc- 

 tion of the selenium in the preparation of muriatic acid. The se- 

 lenium distils over with the muriatic acid into receivers, and in the 

 course of two or three days, falls down as a reddish brown sub- 

 stance. The proportionate quantity produced from the sulphuric 

 acid appears to be very small. 



This selenium has been examined by Mr. Children : a fragment, 



• Quarterly Journal of Science, xvi, p. 157. 



