Herman Boerhaave

Pure Quicksilver contain’d in a dry Glass Vessel that is very clean, being agitated only by a mechanical Shaking or Concussion, gives a soft, black, and very fine Powder.

The Operation.

Having bought 16 Ounces of Quicksilver of the Company at Amsterdam, I strain’d it thro’ a Leather Bag; there remain’d no Dregs: I pounded it a long while with fair Water: The Quicksilver remained pure after pounding: It was then a long time pounded with Sea-Salt, but the Colour of the Salt was not fouled: after having poured Water to this Salt, and to the Mercury, the pounding was repeated; but neither did this change the Colour. In all this Work there appeared nothing black, nothing foreign or foul. Then the Quicksilver was washed and dried, and was bright. I poured it into a clean dry Glass Bottle, made of the dark-green German Glass. At the same Time I plac’d it in a Sand Furnace, with a Fire that almost made the Mercury rise; and to be sure that all the Water was forced out, which is often secretly present in the Mercury, I kept it thus for three Days: Then having thrust a clean dry strong Cork into the Mouth of the Vessel whilst it was yet warm, I fasten’d it up as close as possible. The Head of the Bottle thus closed with a Cork, I dipt into a liquid Cement of Pitch, Rosin, Tallow, and Brimstone, and covered it over with a Linnen Cloth, which I tied fast with Packthread. When the Glass was thus made ready, I put it in a small Wooden Box, which was so fitted to the Bottle, that it touched the Sides of it; and the empty Spaces between the Bottle and the Box, were well filled with Bran. Then I put on a Cover, with a Hole bored in the Middle, for the Top of the Neck of the Bottle to stand a little out. The Glass was immoveable in the Box; and it being thus prepared, I had it fastened to the Hammering Block of a Fulling-Mill, which always moves Night and Day when there is any Wind. Being thus fixed, it was rais’d up and let down by a perpendicular Motion, from the 1st of March, 1732. N. S. to the 13?? of November of the same Year.

The Effect.

The Bottle being opened, there was the same Weight of Mercury, which was covered on all Sides with a very soft, black, copious and fine Powder. I squeez’d it thro’ a clean Leather Bag; the liquid and pure Mercury pass’d thro’. The Powder remained in the Bag of a sharp metallic Taste, somewhat resembling the Taste of Copper or Brass.

Corollaries.

1. Quicksilver, in itself very insipid, by meer shaking, acquires a metallic Taste of Copper.

2. From being very mild, it becomes sharp and penetrating.

3. From a very bright Silver Colour, it turns very black.

4. From a Fluid, it becomes Solid in the Form of Powder.

5. It may therefore be concealed under the Appearance of such a Powder, and deceive the Ignorant.