On llie Gas Blowpipe. 339 



of the earth. The particles must he made to adhere before fusion 

 can he accomplished, and this oxide being much more refractory 

 than the preceding is almost infusible per se, even with the aid 

 of the gas blowpipe." Thus he admits that a substance is almost 

 infusible in his hands, which has been repeatedly fused under 

 mine. 



Experiments and Ohservntions on the Fusion, Volatilization and 

 Combust'ton of the perject Metals. 



Hare, page 305. "Had I sufficient confidence in my own 

 judgement, I should declare that gold, silver and platina were 

 thrown into a state of ebullition by exposure on carbon to the 

 gaseous flame ; for the pieces of charcoal on which they were 

 exposed became washed or gilt with detached particles of metal 

 in parts adjoining the spots where the exposure took place. Some 

 of the particles of the metal thus detached exhibited symptoms 

 of oxidation." 



Comhustion of pure Gold. 



Clark, page 90. " As this experiment affords decisive evi- 

 dence of the combustion of gold, and of course its combination 

 with oxygen, and also exhibits the oxide under a very beautiful 

 appearance, it may be considered as one of the most j)leasing 

 experiments with the gas blowpipe." 



Experiments on Platinum particularly. 



Hare, page 304. " Platina was fused by exposure on carbon 

 to the combustion of hvdrogen gas and atmospheric air. But 

 the fusion of this metal was rapidly accomplished by the gaseous 

 flame either v\hcn exposed to it on carbon or upon metallic sup- 

 j)orts. 



"A small quantity of this metal in its native granular form being 

 strewed in a silver sjjoon and passed under the gaseous flame, tlie 

 tract of tile flame bccanie niarked by the agglutination of the 

 metal ; and when the heat was for some time continued on a small 

 •space, a lump of fused platina became immediately formed. About 

 two penny weights of the native grains of platina when subject to 

 the gaseous flame on carbon, became quickly fused into an oblate 

 spheroid as fluid as mercury. This spheroid after being cooled 

 was exposed as before ; it became fluid in less than the fourth of 

 a minute." 



Hare, 1st part, (ith vol. Philosophical Transactions, page 90, 

 republished Annala de Ckimie, vol. Ix. ])age 81. " Being in- 

 duced last winter to reinstate the apparatus by which these ex- 

 periments were performed, I was enai)Ied to confirm my judge- 

 ment of the volatilization of platina by the observation of Drs. 

 Woodhouse and Seybcrt ; for in the |)rcscnce of these skilful che- 

 niists I completely dissipated some small globules of this metal 

 l)u2 of 



