7i6 
ICE. 
ter were two di ft in "ft fpecies of things, I doubi; not but I 
fhould be ahftvered in the affirmative. Locke. 
You are no. Airer, no, 
Than is the coal of fire upon the ice, 
Or hail-(tone in the fun. Shakefpeare. 
Concreted fugar. 
The younger Lemerv obferves, that ice is only a re- 
eftablifhment of the parts of water in their natural Hate ; 
that the mere abfence of fire is fufficient to account for 
this re-eftablifhment; and'that the fluidity of water is a 
real fufion, like that of metals expofed to the fire ; differ¬ 
ing only in this, that a greater quantity of fire is necefi- 
fary to the one than the other. See the article Chemis¬ 
try, vol. iv. p.205. Galileo was the firft that obferved 
ice to be lighter than the water which compofed it; and 
hence it happens, that ice floats upon water, its fpecific 
gravity being to that of water as eight to nine. This ra¬ 
refaction of ice feems to be owing to the air-bubbles pro¬ 
duced in water by freezing ; and which, being confuler- 
ably larger in proportion to the water frozen, render the 
body fo much fpecifically lighter; thefe air-bubbles, dur¬ 
ing their production, acquire a great ex pan five power, fo 
as to burlt the containing veffels, though ever fo ftrong. 
See Cold, vol.iv. and Freezing, vol. viii. 
M. Mairan, in a differtatibn on ice, attributes thein- 
creafe of its bulk chiefly to a different arrangement of the 
parts of the water from which it is formed; the icy fkin 
on the water being compofed of filaments which, accord¬ 
ing to him, are found to be coiiltantly and regularly join¬ 
ed at an angle of 6o° ; and which, by this angular difpo- 
fition, occupy a greater volume than if they were parallel. 
Hefound the augmentation of the volume of water by freez¬ 
ing, in different trials, a 14-th, an 18th, a 19th, and, when 
the water was'pi'evioufly purged of air, only a 226 part; 
that ice, even after its formation, continues to expand by 
cold ; for, after water had been frozen to fome thicknefs, 
the fluid part being let out by a hole in the bottom of 
the veffel, a continuance of the cold made the ice con¬ 
vex ; and a piece of ice, which was at firft only a 14th 
part fpecifically lighter than water, on being expoied fome 
days to the froft, became a 12th part lighter. .To this 
caufe he attributes the burfting of ice on ponds. But it 
appears from an experiment of Dr. Hooke, in 1663, that 
ic'e refracls the light lefs than water; whence lie infers, 
that the lightnefs of ice, which caufes it to fwim in wa¬ 
ter, is not produced merely by the fmall bubbles which 
are vifible in it, but that it arifes from the uniform con- 
ftitution or general texture of the whole mafs; a fa ft which 
was afterward approved by M. de la Hire. See Hooke’s 
Exper. by Derham, p. 26. 
But a difeovery the moft curious and important of any 
of modern times, relative to the formation of ice, is that 
deftribed by count Rumford in his Effay on the Manner 
in which Heat is propagated in Fluids. 
After proving in a very fatisfaftofy way, that the par¬ 
ticles of fluids are incapable of imparting heat to each other, 
and that, when their temperature is undergoing any change, 
an inteftine motion is kept up'in them, by a lucceffive al¬ 
teration taking place in the fpecific gravity of their parti¬ 
cles, he proceeds to ffiow, that “all bodies are condenfed 
by cold without limitation, 'water 'only excepted. ,” arid de¬ 
ft rites the wonderful effects produced in confequence of 
this particular law. 
“ Though in temperatures above blood-heat (fays count 
Rumford) the exoanfion of w:;ter with heat is very con- 
fiderable, yet in the neighbourhood of the freezing point 
it is aimoft nothing. 'Arid, what is ftiil more remarkable, 
as it is an exception to one of the moft general laws of 
nature with which we are acquainted, when in cooling it 
comes within eight or nine degrees of Fahrenheit’s Icale 
of the freezing point, inftead of going on to he farther 
condenfed as it lofes more of its heat, it aftually expands 
as it grows colder, and continues to expand more and 
more as it is more cooled. 
“If the whole amount of the condenfatioii of any given 
quantity of boiling-hot water, on-being cooled to the 
point of freezing, be divided into any given number of 
equal parts, the condenfations correl'ponding to equal 
changes of temperature will be very unequal in different 
temperatures. Thus, in cooling 22^ degrees of Fahren¬ 
heit’s fcale, (or one eighth part of the interval -between 
the boiling and the freezing- points.) the condenfation 
will be. 
In cooling 22J- 0 , viz 
Condenfation. 
parts. 
viz. from 212 to 
I go *- - 
1 ° y 1 
18 
l8o£ — 
167 
i 6 - 2 
167 -—• 
i++l - 
13-8 
144 -i —’ 
122 
1T *5 
122 — 
99 t - 
9'3 
99i — 
77 
7 ’* 
77 — 
5+2 ' 
T 9 
5+1 — 
32 - 
0*2 
creafe of its fpecific gravity in being cooled 22J- degrees 
of Fahrenheit’s'fcale, is at leaft' ninety times greater when 
the water is boiling-hot, than when it is at the mean tem¬ 
perature of the atmofphere in England, (54Y,) or within 
22J degrees of freezing—(for 18 is to o'z as 90 to 1.) 
“ All liquids, it is true, in cooling, are more condenfed 
by any given change of temperature when they are very 
hot than when they are colder; but thefe differences are 
nothing compared to thofe we-obfe'rve in water. 
“The ratio of the"condenfation in cooling from 212 0 
to 1891°, to that in cooling from 54^° to 32 0 in each of 
the undermentioned fluids, has been fhown, by the expe¬ 
riments of M. de Luc, to be as follows : 
Olive oil - - - as i r Vo to r 
Strong fpirits of wine as xyta to r 
A faturated folution of fea-falt in water as jJ 5 s 5 to 1 
“The difference between the laws of the condenfatioii 
of pure water, and of the fame fluid when it holds in fo¬ 
lution a portion of fait, is ftriking ; but, when we trace 
the ejfeEls which are produced in the world by that ar¬ 
rangement, we (hall be loft in wonder and admiration.” 
After enlarging on this fubjeft, he proceeds thus : “ As 
nourifhment and life are conveyed to all living creatures 
through the medium of water;— liquid■—living water;-— 
to prefeTve life, it was abfolutely neceffary to preferve a 
great quantity of water in a fluid ftate, in winter as well 
as in finnmer. 
“ But in cold climates the temperature of the atmof- 
phere, during many months>in the year, is fo much be¬ 
low the freezing- point, that, had not meafures been taken 
to prevent fo fatal an accident, all the water mull inevi¬ 
tably have been changed to ice, which would infallibly 
have caufed the deftruftion of every living thing. Ex¬ 
traordinary meafures were therefore neceflary for preferr¬ 
ing in a liquid ftate as much of the water exifting in thofe 
climates as is indifpenfably neceflary for the prefervati'on: 
of vegetable and animal life ; and this could only be done 
by contriving matters fo as to prevent this water from 
parting with its heat to the cold atmofphere. 
“ It has been fhown, I believe I may venture to fay 
proved, in the moft fatisfaftory manner, that liquids part 
with their heat only in confequence of their internal, 
motions ; and that the more/apid thefe motion's are, the 
more rapid is the communication of the heat; that thefe 
motions are produced by the change in the lp-ecific gra¬ 
vity of the liquid, occafioned by the change of tempera¬ 
ture, and of courle that they are more rapid, as the fpe¬ 
cific gravity of the liquid is the rnpre changed by any 
given change of temperature. 
“ But it has been fhown that the change in’ the fpecific 
gravity of water is extremely fmall, which takes pkxc'e in 
any given change of temperature, below the mean tempera¬ 
ture of the atmofphere ; and particularly when the tempe¬ 
rature of the water is very near the freezing point; and 
hence it follows, that water muft give oft’ its heat ■ 
flowly when it is near freezing. 
very 
“ But 
