EXPLANATION OF THE EFFECTS 
132 
increases it only to a certain degree. In a strong brine of common 
salt, for example, the disposition of the water to fluidity is so much 
greater than in pure water, that the brine will bear to be cooled down 
to the beginning of Fahrenheit’s scale, or even a few degrees lower, 
without ſhewing any beginning of congelation. But if, by exposing 
to the action of a fufficiently powerful cooling cause, we cool it a 
little more, for example, to five or six degrees below Zero, then the 
chemical attraction of the falt and water for one another begins to be 
overcome by the cohesive attraction of each of these substances; a 
ſmall part of the falt concretes into grains like sand, and falls to the 
bottom, and a small part of the water freezes. This is accompanied 
by the extrication and emergence of a proportional quantity of la 
tent heat, or the conversion of it into sensible heat, which increases 
the sensible heat of the brine a little, and puts'a stop to the farther 
separation of the salt and congelation of the water, until this small 
addition of fensible heat be taken away-again by the cooling cause. 
But as soon as it is taken away, a little more of the falt concretes, 
and a little more of the water freezes. All which repeatedly happens, 
until at last, the whole of the latent having been gradually extricated, 
the salt will be found at the bottom, all in small grains, and the water 
over it all congealed. 
From this we can explain the peculiar phenomena of some of these 
experiments. For example, it is remarkable of the mixture of ice 
and common falt, that it never produces a cold greater than Zero, or 
a few degrees below Zero, but that it continues cold to this degree 
for a considerable length of time, during which the salt and snow are 
gradually melted. Now it muſt necefsarily happen, that as soon as 
they begin to melt, so much of their heat will be converted into la 
tent heat, by the melting of a fmall part of these materials, that their 
remaining sensible heat will be greatly diminifhed. It will be only 
fufficient for heating them to the degree Zero on Fahrenheit’s scale; 
but, when the remaining solid ice and salt are cooled to this degree,