FRE 
very strong brass globe or shell, by freezing 
water in it ; when, from the known thickness 
and tenacity of the metal, it was found that 
the expansive power of a spherule ot water 
only one inch in diameter was sufficient to 
overcome a resistance of more than 27, OOOlbs. 
or 13 tons andq half. See the experiments 
on bursting thick bomb-shells, by freezing 
water in them, by major Edward \\ iiliams, 
of the royal artillery, in the Edin. Philos. 
Trans, vol. ii. 
Such a prodigious power of expansion, al- 
most double that of the most powerful steam- 
engines, and exerted in so small a mass, 
seemingly bv the force of cold, was thought a 
very material argument in favour of those 
who supposed that cold, like heat, is a posi- 
tive substance. Dr. Black’s discovery of la- 
tent heat, however, has now afforded a very 
easy and natural explication of this pheno- 
menon. lie has shewn that, in the act ol 
congelation, water is not cooled more than il 
was before, but rather grows warmer : that 
as much heat is discharged, and passes 
from a latent to a sensible state, as, had it 
been applied to water in its fluid state, would 
have heated it to 133°. In this process the 
expansion is occasioned by a great number of 
minute bubbles suddenly produced. For- 
merly these were supposed to be cold in the 
abstract; and to be so subtle that, insinuat- 
ing themselves into the substance ot the 
fluid, they augmented its bulk, at the same 
time that, by impeding the motion of its 
particles upon each other, they changed it 
from a fluid to a solid. But Dr. Black shews, 
that these are only air extricated during the 
congelation ; and to the extrication of this 
air lie ascribes the prodigious expansive 
force -exerted by freezing water. 1 he only 
question, therefore, now remaining is, By 
what means this air comes to be extricated, 
and to take up more room than it naturally 
does in the fluid ? To this it may be answer- 
ed, that perhaps part ot the heat, which is 
discharged from the freezing water, combines 
with the air in its unelastic slate, and, by re- 
storing its elasticity, gives it that extraordi- 
nary force, as is seen also in the case of air 
suddenly extricated in the explosion of gun- 
powder. 
Cold also usually tends to make bodies 
electric, which are not so naturally, and to 
increase the electric properties of such as are 
so. And it is farther found, that all sub- 
stances do not transmit cold equally well ; 
but that the best conductors of electricity, 
viz. metals, are likewise the best conductors 
of cold, it may farther be added, that when 
the cold has been carried to such an extre- 
mity as to render any body an electric, it 
then ceases to conduct the cold so well as Ire- 
fore. This is exemplilied in the practice of 
tlie Laplanders and Siberians ; where, to ex- 
clude the extreme cold of the winters from 
their habitations the more effectually, and 
yet to admit a little light, they cut pieces of 
ice, which in the winter time must always be 
electric in those countries, and put them into 
their windows ; which they find to be much 
more effectual in keeping out the cold than 
any other substance. 
Cold, or rather the absence of beat, is the 
destroyer of all vegetable life, when increased 
to, an excessive degree. It is found that 
many garden plants and flowers, which seem 
to be very stout and hardy, go off at a little 
F R E 
FRE 
11 3 
increase of cold beyond the ordinary stand- 
ard. And, in severe winters, nature has pro- 
vided the best natural defence for the. corn- 
fields and gardens, namely, a covering of 
snow, which preserves such parts green and 
bealthv as are under it, while such as are un- 
covered by it are either killed or greatly in- 
jured. 
Although the thermometer in this coun- 
try hardly ever descends so low as 0, yet, in 
the winter ot 1780, Mr. W ilson, of Glasgow, 
observed, that a thermometer laid on the 
snow sunk to 25° below 0; and Mr. Dur- 
ham, in the year 1708, observed in England 
that the mercury stood within one-tenth of 
an inch of its station when plunged into a 
mixture of snow and salt. At Petersburg!!, 
'in 1732, the thermometer stood at 28° be- 
low 0 ; and when the French academicians 
wintered near the {tolar circle, the thermo- 
meter sunk to 33° below 0 ; and in the Asia- 
tic and American continents still greater de- 
grees of cold are often observed. 
' The effects of these extreme degrees of 
cold are very surprising. Trees are burst, 
rocks rent, and rivers and lakes frozen several 
feet deep : metallic substances blister the skin 
like red-hot non: the air, when drawn in by 
breathing, hurts the lungs, and excites a 
cough : even the effects- of lire, in a great 
measure, seem to cease ; and it is observed, 
that though metals are kept for a consider- 
able time'" before a strong lire, they will still 
freeze water when thrown upon them. A\ hen 
the French mathematicians wintered at Tor- 
nea, in Lapland, the external ah’, when sud- 
denly admitted into their rooms, converted the 
moisture of the atmosphere into whirls ot snow; 
their breasts seemed to be rent when they 
breathed it, the contact of it was intolerable 
to their bodies ; and the spirit of wine, which 
had not been highly rectified, burst some ot 
their thermometers by the congelation of the ^ 
aqueous part. 
Extreme cold too often proves fatal to ani- 
mals in those countries where the winters are 
very severe: thus 7000 Swedes perished at 
once in attempting to pass the mountains 
which divide Norway from Sweden. But it 
is not necessary that the cold, in order to 
prove fatal to human life, should be so very 
intense as has just been mentioned ; it is only 
requisite’ to be a little below 32° of Fahren- 
heit, or the freezing point, accompanied with 
snow or hail, from which shelter cannot be 
obtained. The snow which falls upon the 
clothes, or the uncovered parts ot the body, | 
then melts, and by a continual evaporation j 
carries off the animal heat to such a degree, ! 
that a sufficient quantity is not left for the 
support of life. In such cases, the person 
first feels himself extremely chill and uneasy ; : 
he turns listless, unwilling to walk or use ex- ; 
ereise to keep himself warm, and at last turns j 
drowsy, sits down to refresh himself witli 
sleep, but wakes no more. 
With regard to the term congelation, it is 
applied to water when it freezes into ice ; to 
metals, when they resume their solid form 
after being melted by heat ; or to glass, wax, j 
pitch, tallow, &c. when they harden again j 
after having been rendered fluid by heat. But 
it differs from crystallization, which is rather 
a separation of the particles of a solid from a 
fluid in which it had been dissolved more by ; 
the moisture than the action of heat. 
The process of congelation is always at- , 
tended with the emission of heat, as is found 
by experiments on the freezing of water, 
wax, spermaceti, &c. ; for in such cases it is 
always found that a thermometer dipt into the 
fluid mass keeps continually descending as 
this cools, till it arrives at a certain point, be- 
ing the point of freezing, which is peculiar 
to each fluid, where it is rather stationary, 
and then rises tor a little, while the congela- 
tion goes on. 
Freezing-point, denotes the point or 
degree of cold, shewn by a mercurial ther- 
mometer, at which certain fluids begin to 
freeze, or, when frozen, at which they begin 
, to thaw again. On Fahrenheit’s thermometer 
this point is at + 32 for water, and at — 40 
for quicksilver, these fluids freezing at those 
two points respectively. It would also be 
well if the freezing points for other fluids 
were ascertained, and the whole arranged in 
a table. See Thermometer. 
Frfezing-rain, or raining ice, a very 
uncommon kind of shower, which fell in the 
west of England, in December 1(>72, of 
which we have various accounts in the Phi- 
losophical Transactions. T his rain, as soon 
as it touched any thing above ground, as a 
bough, &e. immediately settled into ice ; 
and, by multiplying and enlarging of the ici- 
cles, broke all down with its weight. I lie 
rain that fell on the snow immediately froze 
into ice, w ithout sinking in the snow at all. 
It made an incredible destruction of trees, 
beyond any tiling in all history. “ llad it 
1 concluded with some gust of wind (says a 
gentleman on the spot), it might have been 
of terrible consequence. I weighed the sprig 
of an ash-tree, ot just three-quarters of a 
pound, the ice on which weighed Hi pounds, 
borne were frightened with the noise in the 
air, till they discerned it w ; as the clatter ot 
icy boughs, dashed against each other.’ 
Tltis phenomenon, however, is not uncom- 
| moil in a less degree, and depends wholly on 
the nice balance of temperatures in the rain 
and atmosphere. Dr. Beale observes, that 
there was no considerable frost observed oil 
the ground during the whole; whence he 
concludes, that a frost may be very intense 
and dangerous on the tops of some hills and 
plains ; w hile in other places it keeps at two, 
three, or four feet distance above the ground, 
rivers, lakes, &c. and may wander about very 
furious in some places, and remiss in others 
not far off. The frost w r as followed by glow- 
ing heats, and a wonderful forwardness of 
flowers and fruits. 
Freezing mixture. See Cold. 
FREIGHT, or Fraight, in navigation 
and commerce, is the consideration of mo- 
ney agreed to be paid for the use or hire of a 
ship, or, in a larger sense, the burthen of such 
ship. 
The freight is most frequently determined 
for the whole voyage, without respect to 
time: sometimes it depends on time; in the 
former case it is either fixed at a certain sum 
for the whole cargo, or so much per ton, bar- 
rel bulk, or other weight or measure, or so 
much per cent, on the value of the cargo. 
If a certain sum is agreed on for the freight 
of the ship, it must all be paid, although the 
ship when measured should prove less, unless 
the burthen is warranted. If the ship is freight- 
ed for transporting cattle or slaves at so much 
per head, and some of them die on the pas- 
sage, freight is only due for such as are deli- 
