F R E 
cold I have ever experienced in Siberia: the air was calm 
at the time, and feemingly thickened ; fo that, though 
the tky was in other refpefts clear, the fun appeared as 
through a fog. I had only one fmall thermometer left, 
in which the fcale went no lower than —'7°; and on the 
6th in the morning, I remarked that the quickfilver in it 
funk into the ball, except fome fliort columns which 
(luck fad in the tube. When the ball of the thermome¬ 
ter, as it hung in the open air, was touched with the fin¬ 
ger, the quickfilver rofe; and it could plainly be feen 
that the folid columns (luck and refilled a good while, 
and were at length pulhed upward with a fort of violence. 
He alfo placed upon the gallery, on the north fide of his 
houfe, fome quickfilver in an open bowl. Within an 
hour he found the edges and furface of it frozen folid ; 
and fome minutes afterward the whole was condenfed by 
the natural cold into a foft mafs very much like tin. 
While the inner part was dill fluid, the frozen furface 
exhibited a great variety of branched wrinkles; hut in 
general it remained pretty fmooth in freezing. The con¬ 
gealed mercury was more flexible than lead; but on be¬ 
ing bent fhort, it was found more brittle than tin; and 
■when hammered out thin, itfeemed fomewhat granulated. 
When the hammer was not perfedlly cooled, the quick¬ 
filver melted away under it in drops; and the fame thing 
happened wdien the metal was touched with the finger, 
by which alfo the finger was immediately benumbed. 
When the frozen mafs was broken to pieces in the cold, 
the fragments adhered to each other and to the bowl in 
which they lay. In the warm room it thawed on its fur¬ 
face gradually, by drops, like wax on the fire, and did 
not melt all at once. Although the frofi: feemed to abate 
a little towards night, yet the congealed quickfilver re¬ 
mained unaltered, and the experiment with the thermo¬ 
meter could ftill lae repeated. On the 7th of December 
he had an opportunity of making the fame obfervations 
all day ; but fome hours after funfet, a northwefl wind 
fprung up, which raifed the thermometer to —46?, when 
the mafs of quickfilver began to melt. 
The experiments of Mr. Braun were fuccefsfully re¬ 
peated at Gottingen, in 1774, by M. Blumenbach ; be¬ 
ing encouraged to this attempt by the exceflive cold of 
the winter that year, efpecially the night of January the 
nth, when he made the experiment, the thermometer 
(landing at —10 in the open air. M. Blumenbach at five 
in the evening, put three drachms of quickfilver into a 
fmall fugar glafs, and covered it with a mixture of fnow 
and Egyptian fal ammoniac, fetting the glafs out in the 
air upon a mixture alfo of fal ammoniac. At one the 
next morning, the mercury was found frozen quite folid, 
and hard to the glafs; and did not melt again till feven or 
eight the next morning. The colour of the frozen mer¬ 
cury was a dull pale white with a bluifli call, like zinc, 
very different from the natural appearance of quickfilver. 
In 1775, by fimilar means, quickfilver was twice frozen 
by Mr. Hutchins, governor of Albany fort, in Hudfon’s 
bay, viz. in the months of January and February of that 
year. And the fame was done on the 28th of January, 
1776, by Dr. Lambert Bicker, fecretary of Rotterdam. 
The temperature of the atmofphere was then at +2“; 
and the lowed: it could reduce the thermometer by arti¬ 
ficial cold, was —94; when, on breaking the glafs, the 
mercury was found frozen. 
In the beginning of 17S0, M. von Elterlein, of Vyte- 
gra, a town of Ruflia, in iat. 61° north, and Ion. 36° 
call, froze quickfilver by natural cold. On the 4th of 
January, 1780, the cold being increafed to —34 that 
evening at Vytegra, he expofed to the open air three 
ounces of very pure quickfilver in a china tea-cup, co- 
vered with paper pierced full of holes. Next day, at 
eight in the morning, he found it folid, and looking like 
a piece of call lead, with a conliderable depreflion in the 
middle. On attempting to loofen it in the cup, his knife 
raifed lhavings from it as if it had been lead, which .re¬ 
mained flicking up j and at length the metal feparated 
F R E 31 
from the bottom of the ettp in one mafs. He then took, 
it in his hand to try if it would bend: it was flilF like 
glue, and broke into two pieces; but his fingers immr- 
diately loft all feeling, and could fcarcely be reftored in 
an hour and a half by rubbing with fnow. At eight 
o’clock the thermometer flood at —57 ; but half alter 
nine it was rifen to—40; and then the two pieces of 
mercury which lay in the cup had loft fo much of their 
hardnefs, that they could no longer be broken, or cut into 
fliavings,but refembled a thick amalgam, which, thotigh 
it became fluid when prefled by the fingers, immediately 
afterwards refumed the confidence of pap. With the 
thermometer at —39, the quickfilver became fluid. The 
cold was never lefs on the fifth than —28, and by nine in 
the evening it had increafed again to —33. This expe¬ 
riment feems to fix the freezing point of mercury at —40 
of Fahrenheit’s thermometer, or 40 below o; which is 
72° below the freezing point of water. 
In the winter of 1781-2, Mr. Hutchins refumed the 
fubjedl of freezing quickfilver by artificial cold, with 
fuch fuccefs, that from his experiments and thofe of 
M. von Elterlein, laft mentioned, the freezing point of 
mercury is now almoft as well fettled, viz. at —40, as 
that of water is at-{-32. Other philofophers indeed had. 
not been altogether inattentive to this fubjecT:. Profeftbr 
Braun himfelf had taken great pains to inveftigate it; 
but for want of a proper attention to the difference be¬ 
tween the contraction of the fluid mercury by cold, and 
that of the congealing metal by freezing, he could not 
determine any thing certain concerning it. 
An inftance of the natural congelation of quickfilver 
alfo occurred in Jemptland, one of the provinces of Swe¬ 
den, bn the ift of January, 1782; and again, on the 2<Sth 
of the fame month, Mr. Hutchins oblerved the fame 
effect of the cold at Hudfon’s bay; when he found that 
at the point of its freezing a mercurial thermometer flood 
at —40, and a fpirit thermometer at —30. On this fub- 
jeCl, fee the Philofophical TranfaClions, vol. li. p.672; 
Hi. 156; Ixvi. 174; Ixxiii. 303 and 325; Ixxvi. 241; 
Ixxvii. 283 ; Ixxviii. 43 ; and feveral others, particu¬ 
larly Ixxix. 199, &c. being experiments on the congela¬ 
tion of quickfilver in England, by Mr. Richard Walker, 
where he proves that mercury may be frozen not only in 
England in fummer, but even in the hotteft climate, at 
any feafon of the year, and v.'ithout the ufe of ice or fnow. 
FREEZ'ING POINT, the point or degree of cold, 
fliewn by a mercurial thermometer, at which certain 
fluids begin to freeze, or, when frozen, at which they 
begin to tiiaw again. On Fahrenheit’s thermometer, this 
point is at -J-32 for water, and at —40 for quickfilver, 
thefe fluids freezing at thofe two points refpeClively. It 
would alfo be well if the freezing points for other fluids 
were afeertained, and the whole arranged in a regular table. 
FREEZ'LAND PEAK, a cape on Sandwich Land, in 
the South Pacific Ocean, Lat. 59. 2. S. Ion. 27, W. 
Greenwich. 
FREGEL'LA, in ancient geography, a famous towm 
.of the Volfci in Italy on the Liris, deftroyed for revolting 
from the Romans. Livy. 
FREGE'NE, a town of Etruria. Pliny. 
FRE'HER (Marquard), an eminent jurift, born in 
1565, at Augfburg, of a family diftinguilhed in the law 
and magiftracy. He ftudied firll at Altdorff, and was 
thence fent to Bourges, where he received his licence in 
law from the celebrated Cujas, in 1585. He was made a 
counfellor to the elector palatine, John-Calimir, and in 
1596 obtained the profelforfhip of'law in the univerfity of 
Heidelberg. The elector Frederic IV. employed him in 
various important concerns, and created him vice-prefi- 
dent of the fenate. He diftinguiflied himfelf by‘his dex¬ 
terity in negociations at the courts of the king of Poland 
and feveral German princes; at the fame time he did not 
negledl his literary purfuits, which were particularly 
turned to hiftory and antiquity. Fie died at Heidelberg 
in 1614, at the age of forty-nine, leaving behind him a 
variety 
