cooling of Water below its freezing Point. 141 
one another ; and hence fuch water is inftantly brought ta 
freeze. Indeed it is this circumftance which conftitutes the 
freezing point ; for that point is evidently nothing elfe but 
the degree of cold which renders the particles of any fluid 
incapable of refifting the attractive power of other particles of 
the fame fluid, already reduced into a i'olid form : and the fact, 
that the cold of the freezing point is lefs than the fluid will 
otherwife bear, feems a proof that when the particles have 
acquired this arrangement of folidity, their attractive powers 
are the ftrongefl j fo that the difference between the freezing 
point, and the greateft cold the fluid will bear, may be conli- 
dered as the meafure of this additional attractive force. 
Agitation may be eafily conceived, by the various motions 
impreflfed upon the particles, to occafion fome of them to apply 
their polar points in a more advantageous pofition, or even to 
force them nearer together ; and thefe effeCts are more likely to 
be produced by an intimate agitation, than by a general motion 
of the whole mafs. The want of tranfparency, in certain 
cafes, as in fome folutions of falts, feems not owing to the 
prefence of foreign matters, but rather to depend upon a par- 
ticular arrangement of the combined particles, which may 
difpofe thofeof the water to join more readily, and detach thole 
of the fait. Extraneous fubftances, befides their indirect 
effeCt, may, by various chances attending their floating in the 
water, throw the particles into favourable fituations ; and if 
thin plates are more difpofed to freeze, it may be, that the 
particles of water in fuch are more free from counteracting 
attractions. 
Sudden cooling may promote congelation Amply by occa- 
fioning the water at the bottom and fides of the veflel to ac- 
quire a greater degree of cold than the reft. But perhaps it 
may have alfo another effeCt, admitting of a particular expla- 
nation. 
