On the supposed new Metal lately discovered in Platina. 29 



when reduced in the melting furnace yields-a compound con- 

 sisting of 0*75 of tin and 0*25 of copper. This metal is 

 put together with that obtained from the vitreous refuse 

 into the calcining furnace, and the whole oxidized to a cer^ 

 tain point. The first oxide which is formed is white and 

 light, but it gradually becomes coloured. At this period 

 the oxide produced is not merely oxide of tin, but a mix- 

 ture of oxide of copper and oxide of tin. The formation 

 of this oxide serves the operator to judge of the quality of 

 his oxidizing metal ; for, the moment this oxide begins to 

 appear, the metal consists of equal parts of tin and copper, 

 and it ceases to appear when the metal is in the state of bell- 

 metal : just before this takes place the oxide becomes very 

 black. 



As the metal is brought to this standard it is drawn from 

 the furnace, in order to procure from it again, as before, 

 metallic copper and a vitreous oxide 3 which is again treated 

 as already stated. 



All the oxide obtained during the different processes 

 must be reduced by means of charcoal in the melting 

 furnace. 



If it should happen that the tin obtained by these pro- 

 cesses contains copper, let it be again fused, and cool 

 slowly so far till a piece of paper let fall upon it does not 

 become charred. The tin may then be ladled off, and the 

 copper will be found at the bottom adhering to a portion 

 of tin only, which may be got rid of by oxidation. 



V. On the supposed new Metal lately discovered in Platina* 

 By Jos. Hume, Esq. 



To Mr. Tilloc/u 



DEAR SIR, 



X he new metal lately obtained from crude platina seems, 

 in many respects, so nearly allied to tungsten that I cannot 

 but entertain strong suspicions of their identity ; and that 

 the difference, if there be any, possibly arises more from 

 one or the other retaining a slight admixture of chrome or 

 its acid, or some other trifling alloy not yet discovered, 

 than from any specific distinction in their nature. As crude 

 platina is now found to be generally contaminated by various 

 substances, such as iron, copper, titanium, chrome, silex, 

 and this metal, we cannot be much surprised should one or 

 more of these so far influence the new metal, supposing it 

 4 "to 



