Experiments on Cold.'- 393 
it is not improbable, had the prefent experiment been tried 
with more precaution and addrefs, that the refult would have 
been hill more remarkable. There was employed only about a 
pint of alcohol, but the proportion of fnow was not then 
attended to, and the thaw coming foon afterwards prevented 
a repetition of the experiment. 
I am, See.: 
p O S T S C ft I E TE 
1 beg leave to add, that * the water mentioned as produced 
from the fuperficial fnow has been examined by feveral chy- 
mical trials, with a view of difeovering if it differed in any 
refpefl from the water obtained from fnow gathered at 
confiderable depths,- and near the ground. Had the 
atmofphere, when the thermometers pointed fo low, been 
difpofed to furnifh any faline principle, the union of fuch an 
ingredient with the fnow would have tended to produce an 
excefs o£ cold at the furface, fimilar to what was then ob- 
ferved. Or if the fnow at thefe low temperatures had acquired 
any remarkable power of dephlogifHcating the air in contact 
with it, a cooling procefs at and near the confines of the fnow 
and air might thereby have been maintained. I11 either of 
thefe cafes, fome very fenfible indications of a faline or of a 
phlogiflic principle might be expeded on the water given :by 
the:.- 
