334 On the Gas Blowpipe. 



gaseous flame a powerful attraction is exerted between iron and 

 the earths." 



Hare, page 306. " There is a peculiar species of native coal 

 found on the banks of the Lehigh in this State, which is extremely 

 difficult to ignite ; which when exposed to a high degree of heat, 

 and a copious blast of air, burns, yielding an intense heat without 

 either smoke or flame, and leaving little residue. By exposure 

 to the gaseous flame on this coal, both magnesia and lime ex- 

 hibited strong symptoms of fusion. The former assumed a glazed 

 and somewhat globular appearance, the latter became converted 

 into a brownish semivitrecus mass." 



Silliman, page 109. " A piece of lime from the Carrara mar- 

 ble was strongly ignited in a covered platinum crucible ; one an- 

 gle of it was then shaped into a small cylinder, about one-fourth 

 of an inch high, and somewhat thicker than a great pin. The 

 cylinder remained in connexion with the piece of lime. This 

 was held by a pair of forceps, and thus the small cylinder of lime 

 was brought into contact with the heat without danger of being 

 blown away, and without a possibility of contamination. There 

 was this further advantage, (as the experiment was delicate, and 

 the determination of the result might be difficult,) that as the cy- 

 linder v.'as held in a perpendicular position, if the lime did really 

 melt, the column must sink, and become at least to a degree 

 blended with the supporting mass of lime. When the compound 

 flame fell upon the lime, the splendour of the light was perfectly 

 insupportable by the naked eye; and when viewed through deep 

 coloured glasses (as indeed all these experiments ought to be) 

 the lime was seen to become rounded at the angles, and gradually 

 to sink, till in the course of a few seconds only a small globular 

 protuberance remained, and the mass of supporting lime was su- 

 perficially fused at the base of the column for a sj^ace of half an 

 inch in diameter. The protuberance, as well as the contiguous 

 portion of lime, was converted into a perfectly white and glistening 

 enamel. A magnifying glass discovered a few minute pores, but 

 not the slightest earthy appearance. This experiment was re- 

 peated several times, and with uniform success ; may not lime 

 therefore be added to the list of fusible bodies ?" 



Clark, page 47. " Lime in a state of perfect purity and in the 

 pulverulent form being placed within a platinum crucible, and 

 exposed to the flame of the blowpipe, its upper surface became 

 covered with a limpid botryoidal glass, resembling hyalite; the 

 inferior surface was quite black. Its fusion was accompanied by 

 a lambent purple flame. This colour therefore may be considered 

 as a characteristic hue of one at least of the oxides of calcium." 



Clark, page 49, No. 6. " Compact transition limestone (lime- 

 stone of Parnassus). The specimen was taken from the summit of 



Parnassus 



