Herman Boerhaave

Mercury kept under boiling Water, is not rais’d from the Bottom of the Vessel.

The Operation.

I pour’d a Drachm of Mercury twice distilled into a Glass Urinal, which I fill’d with Rain Water: Then I set the Vessel upon the naked Fire: The Water boil’d strongly for eight Hours, yet so that there still was some Water swimming over the Mercury. The Mercury being afterwards weigh’d, gave a Drachm without any Loss.

Again; I pour’d a Drachm of Mercury into a clean dry Glass Vessel. This I so fitted in a Kettle, that it cou’d not fall aside. I filled the Kettle with Water; I made the Water boil eight Hours. This Vessel was cylindrical, open, two Inches and one half deep, and placed so that the Water cou’d not get in. After this was so done, the Mercury weighed one Drachm without any Loss.

I put pure Mercury into a Glass Vessel, I poured Water upon it; and setting the Still over it, I boil’d it for a long while: No Mercury ascended. I continued boiling, till all the Water being gone out, the Mercury remained dry in the Bottom of the Vessel. However, I did not then increase the Fire; but the Mercury presently ascended to the Sides of the Vessel, and into the Head. The Reason of this appears from what I have written in my chemical Institutions about Water and Fire.