Experiment* on freezing Mixtures . 257 
merely to accident, and to both acids having happened to be of 
that precife degree of heat before the experiment began, that 
their heat after dilution fhould coincide with the freezing point 
anfwering to their new ftrength. The true caufe feems to be 
as follows. It will be (hewn in Art. 16. and 17. that the 
freezing point of thefe acids, when diluted as in the foregoing 
experiments, is much lefs cold than when they are confiderably 
more diluted ; and it was before fhewn to be much lefs cold 
than when not diluted ; fo that there mu ft be a certain degree 
of ftrength, not very different from that to which thefe acids 
were reduced by dilution, at which they freeze with a lefs 
degree of cold than when they are either ftronger or weaker.' 
Now in thefe experiments, the temperature of the liquors be- 
fore dilution was below this point of eafieft freezing, and a great 
deal of the acid was in a ftate of congelation all the time of 
dilution; the confequence of which is, that when they were 
diluted to the ftrength of eafieft freezing, they would alfb be 
at the heat of eafieft freezing ; for they could not be below 
that point, becaufe, if they were, fo much of the acid would 
immediately freeze as would raife them up to it ; and they 
could not be above it, for, if they were, fo much of the con- 
gealed acid would diffolve as would fink them down to it. 
After they were arrived at this ftrength of ealieft freezing, the 
addition of more fnow would produce cold, unlefsthis ftrength 
be greater than that at which the addition of a fmall quantity 
of fnow begins to produce cold ; but even were this the cafe, 
heat would not be produced, but the temperature of the acids 
would remain ftationary until they were fo much diluted that 
the addition of more fnow fhould produce cold. So that, in 
either cafe, the heat of the acids, at the time that the addition 
of frefh fnow began to produce cold, muft be that of eafieft 
Vol. LXXVI, L 1 freezing • 
