Art. XXXIII.—On the Fusibility of Platinum in the Blowpipe Flame.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 2, 1869, Page 155

Art. XXXIII.—On the Fusibility of Platinum in the Blowpipe Flame. By W. Skey, Analyst to the Geological Survey of New Zealand. [Read before the Wellington Philosophical Society, November 13, 1869.] The metal platinum has hitherto been supposed to be infusible, except at a temperature that is so high, as to be incapable of being produced by the common blowpipe; at least I have carefully searched for any statements to the contrary without success. When I was lately engaged in studying the effects of the hot-blast blow-pipe flame, the results of which investigation have already been communicated to the society (See p. 148), I found it necessary to test, with accuracy, the degree of fusibility of platina; and discovered that if the loss of heat from the flame, by conduction, was guarded against, platinum can be fused with an ordinary blowpipe blast through a candle flame. The method adopted was to substitute, for the metallic nozzle generally employed, a tube of clay or glass, either of which is a feeble conductor of heat, as compared with metals. By this means fine platinum points were fused in an unmistakable manner, to beads. The blast was that ordinarily used in the laboratory by the use of the hydrostatic blowpipe, the flame being that of a stearine candle. As it might be urged that, perhaps, the platina I treated, might contain an admixture of more fusible metal, and that its melting point might thus be reduced, I prepared some of the platina for special trial, which was absolutely free from such fusible metals. As the fusing point of platinum has been ascertained to be 4593° Fah., we must, from the above experiment conclude, that if proper precautions

are taken to prevent loss of heat by conduction, this high temperature can be produced by the ordinary blowpipe operating upon flames of this description.