The Sincerely Discovered Art of Assaying and Refining of the Venetians

the parting acid away from it, then put it into a small copper dish, which is about the width of a groschen. You must not touch it, however, so that you do not break it, until it becomes hard. And let it afterwards become dry by degrees on the fire in the little dish, yet so that it does not become too hard. Then draw it to the balance; what it points to, that is what a mark of fine gold holds. If it is too good, you must add copper to it; if it is too meager, you must add fine gold to it. And thus you must do for every gold-test, unless it is fine gold.

To test ore.

Take the ore, roast it on a shard until it has glowed through almost entirely. Then pound it to powder, and weigh 1 centner A standard unit of weight, about 100-110 lbs. of it, and take 2 lots of lead, and set it on a shard in a testing-furnace, or otherwise in a coal-fire, surrounded with stones, and blow until it goes finely. So a small block The assay button. becomes of it. If one has it in a testing-furnace or under a muffle, one does not need to blow, it gives enough heat otherwise. Afterwards one knocks the slag away from it, and sets the same small block on a cupel, lets it go off, and if it has gone off, one finds what it holds.

To grain lead.

Let the lead become hot, and pour it into a