on Mr. hutciiins’s Experiments. $ j j 
This flie we, that water is capable of being cooled confidera- 
bly below the freezing point, without any congelation taking 
place ; and that, as loon as by any means a fmall part of it is 
made to fieeze, the ice Ipreads rapidly through the remainder 
cf the water. d he caufe of the rife of the thermometer, 
when the water begins to freeze, is the circumftance now pretty' 
well known to philofophers, that all, or almoft all, bodies by 
changing from a fluid to a folid ftate, or from the flate of an 
elaflic to that of an unelaftic fluid, generate heat ; and that 
cold is produced by the contrary procefs. This explains all the 
circumflances of the phenomenon perfectly well ; for as foon 
as any part of the water freezes, heat will be generated thereby 
in confequence of the abovementioned law, fo that the new 
formed ice and remaining water will be warmed, and muft con- 
tinue to receive heat by the freezing of frefh portions of water, 
till it is heated exactly to the freezing point, unlefs the water 
could become quite folid before a fufficient quantity of heat was 
generated to raife it to that point, which is not the cafe ; and it 
is evident, that it cannot be heated above the freezing point, 
for as foon as it comes thereto, no more water will freeze, and 
confequently no more heat will be generated. 
The reafon why the ice fpreads all over the water, inflead of 
forming a folid lump in one part, is, that as foon as any fmall 
portion of ice is formed, the water in contact with it will be fo 
much warmed as to be prevented from freezing ; but the wa- 
ter at a little diftance from it will hill be below the freezing 
point, and will confequently begin to freeze* 
point ; but in this experiment the water was cooled hot more than one or two degrees 
below freezing; and it ihouid feem, that the more the water is cooled below that 
point, the more rapidly the ice {hoots, and the incloled thermometer riles. 
Vol. LXXIII. T t 
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