Page:The chemical history of a candle.djvu/202

200 shall have great difficulty in pulling them apart, though they are joined only at the point where the two cylindrical surfaces came together. And now I have succeeded in pulling the wire apart, the division is not at the point of welding, but where the force of the pincers has cut it, so that the junction we have effected is a complete one. This, then, is the principle of the manufacture and production of platinum in the old way.

The treatment which Deville proposes to carry out, and which he has carried out to a rather large extent in reference to the Russian supply of platinum, is one altogether by heat, having little or no reference to the use of acids. That you may know what the problem is, look at this table, which gives you the composition of such a piece of platinum ore as I shewed you just now. Wherever it comes from, the composition is as complicated, though the proportions vary:—