558 
MERCURY. 
thermometer broken as soon as the metal was con- 
gealed ; when it appeared that the mercury was 
changed into a solid and shining metallic mass, 
which flatted and extended under the strokes of a 
pestle, being rather less hard than lead, and yield- 
ing a dull sound like that metal. M. Epinus made 
similar experiments at the same time, employing as 
well thermometers as tubes of a larger bore ; in 
which last he remarked that the quicksilver fell 
sensibly on being frozen, assuming a concave sur- 
face, and likewise that the congealed pieces sunk in 
fluid mercury. In their further experiments they 
invariably found that the mercury sunk lower when 
the whole of it was congealed, than if any part of it 
remained fluid ; all tending to prove that mercury, 
contrary to water, contracts in freezing. It was fur- 
ther observed, that the mercury, when congealed, 
looked like the most polished silver, and when 
beaten flat it was easily cut with a penknife, like 
soft thin sheet-lead. 
It is a singular fact, that where Pallas witnessed 
the spontaneous congelation of mercury the climate 
is colder than in many countries of Europe eight or 
ten degrees more to the northward, and this differ- 
ence is more particularly sensible as you advance to 
the east. Patrin tells us that the environs of the 
river Amour, which are in the same latitude as 
Flanders, are more icy than the banks of the Neva. 
Mercury is the heaviest of all metals except gold 
and platina, and is almost as unalterable as those 
precious substances. Boerhaave digested quicksilver 
