356 
Tin. 
riatic, and two of nitric acid, and after they have stood 
together 24 hours, digest for some time in a gentle sand 
heat ; then dilute with a little water, and filter. Let the 
sulphur of the residuum be burned off on a test, and treat 
what remains with fresh nitro- muriatic acid. The part 
not soluble being ignited with a little wax, the iron will 
be reduced, and the remainder is silex from the matrix. 
The solutions are to be precipitated with carbonat of pot- 
ash ; the precipitate redissolved in muriatic acid diluted 
with three parts of water ; and a stick of pure tin immers- 
ed in this solution. The copper will be deposited on the 
tin, and leave the solution colourless. The copper being 
dissolved by brisk digestion in nitric acid, if any tin be 
mixed with it, this will fall down in the state of white 
oxyde. The tin may be separated by zinc, as in the pre- 
ceding instance ; and what was dissolved from the stick 
used in precipitating the copper, must be deducted from 
its weight. 
In the dry way, these ores, after pulverization and se- 
paration of the stony matter by washing, are to be melted 
with a mixture of double their weight of a flux, consist- 
ing of equal parts of pitch and calcined borax, in a cruci- 
ble lined with charcoal, and to which a cover is luted ; 
fusion should be speedily procured. 
Bergman recommends a mixture of one part of the ore 
with two of tartar, ^one of black flux, and half a part of 
resin this is to be divided into three parts, and each suc- 
cessively projected into a crucible heated white, and im- 
mediately covered after the foregoing portion ceases to 
flame ; the whole operation takes up but seven minutes, 
or less. 
Previous to smelting in the large way, the impure ores 
of tin must be cleansed as much as is possible from all 
heterogeneous matters. This cleansing is more necessa- 
ry in ores of tin than of any other metal, because in the 
* The tartar and black flux are bad. T, C* 
