of lime of this sort, he is able to get a vessel to contain these metals with scarcely any loss of heat. He puts the blowpipes through these apertures, and sends down these gases upon the metals, which are gradually melted. He then puts in more metal through a hole at the top. The results of the combustion issue out of the aperture which you see represented. If there be strips of platinum, he pushes them through the mouth out of which the heated current is coming, and there they get red-hot and white-hot before they get into the bath of platinum. So he is able to fuse a large body of platinum in this manner. When the platinum is melted, he takes off the top and pours out from the bottom piece, like a crucible, and makes his cast. This is the furnace by which he fuses his forty pounds or fifty pounds of platinum at once. The metal is raised to a heat that no eye can bear. There is no light, and shadow, no chiaro-oscuro there; all is the same intensity of glow. You look in, and you cannot see where the metal or the lime is; it is all as one. We have, therefore, a platform with a handle, which turns upon an axis, that coincides with the gutter that is formed for the pouring
Page:The chemical history of a candle.djvu/220
This page has been validated.
218
LECTURE ON PLATINUM.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/e/e9/The_chemical_history_of_a_candle.djvu/page220-1024px-The_chemical_history_of_a_candle.djvu.jpg)