Herman Boerhaave

To examine the Powder produced by 2?, 4??, 5??, 6?? Operations.

The Operation.

Two Ounces, 1 Drachm, and 51 Grains of that Powder, I put into a clean Glass Retort, covered with a Coat of Clay, mix’d or temper’d with Sand. I heated it by Degrees, till at last the Retort, the bare Fire being laid over it, grew almost red with the bright Fire that covered it in the Sand Furnace, for three Hours together.

The Effect.

There came out 1 Ounce, and half a Drachm of pure Mercury revived from that Powder: There remain’d in the Bottom of the Retort seven Drachms and a half of the bright red Powder. Something stuck in the Neck of the Retort, and in the Glass Vessel applied to the Neck of the Retort. Perhaps some was dissipated by so great and lasting a Fire.

Corollaries.

1. The Mercury returns out of the Powder into which it was turned by the Fire.

2. Being revived, it recovers all its former Properties, and lays aside all those that it had acquir’d. Out of the Powder comes the same Mercury as at first.

3. The acquired Fixedness does not bear a great Fire.

4. Yet in that Powder one part is more fixed than another; this still remains a Powder, that returns to Mercury.