144 * -Dr. Blagden’s Experiments on the 
the fame veflel, whilft ftill warm, in the frigorific mixture. The 
mixture was made to a£t very (lowly, fo that the operation con- 
tinued more than an hour. When the immerfed thermometer 
had lunk to 20°j, the water was dill fluid : I then (hook it 
confiderably, but no ice formed. After waiting fome time, 
and finding the thermometer would fink no lower, becaufe by 
the length of the procefs the fnow of the mixture was almod 
confumed, I added fome frelh materials, which could not be 
done without (haking the tin cup. Still, however, the 
water did not freeze inftantly, though it (hot as foon after 
as it can be (uppofed to have felt the influence of the new 
frigorific mixture. When this water was cooled to 24 0 , I 
tried the temperature of the air near its furface, and found 
it 34 0 or 35 0 , the experiment being performed in a room with, 
a fire. 
Another time I cooled fome diftilled water, covered with 
oil, below 21 0 , by fimilar precautions. 
This, however, is by no means the greateft cooling of 
which water is fufceptible. I11 Fahrenheit’s experiment, 
with an exhaufted globe half full of boiled rain water, it 
feems to have been cooled to 1 5 0 *. M. de Luc likewife in- 
forms us, t that having filled a thermometer with fome water 
he had purged of air by the means defcribed in his great work 
upon the atmofphere, he expofed it to a cold which funk a mer- 
curial thermometer to i4°of Fahrenheit’s fcale. The water 
in the thermometer continued tranfparent, and upon breaking 
the ball was found to be liquid, but froze that inftant. In 
fome of my experiments too with mixtures of nitrous acid 
and water, the liquor bore to be cooled as much as 13 degrees 
* Philofophical Tranfaflions, Vol. XXXIII. p. 81. 
f Idees fur la Mcteorologie, Tom, II. p. 105. 
below 
