on Mr, hutchins’s Experiments. « r - 
la the fecond experiment, tried with the fame apparatus, 
the ivory thermometer quickly funk to - 43 0 ; but, in about half 
a minute, role to - 40°, where it remained fationary for un- 
wards ot 1/. It appears, therefore, that in this experiment 
the quickfilver was. cooled 3 0 below the freezing point, witli- 
out lofing its fluidity ; it then began to freeze, and the inclofed 
thermometer immediately rofe to - 40° : fo that this experi- 
ment, befides confirming the former, fliews, that quickfilver 
is capable of being cooled a little below the freezing point with- 
out freezing ; and that it luddenly rifes up to it as loon as it be- 
gins to lofe its fluidity. 
In this experiment the cold was carried far enough to freeze 
the quickfilver in the ivory thermometer, which was not the 
cafe in the former: for after it had remained 17' fationary 
at -40% it began to fink again, and in about a minute funk 
to — 44°| ; it then funk infantaneoufly to -92% and foon 
after remained fixed for an hour and a quarter at 95 0 ; being 
then left without examination for three-quarters of an hour, 
the mercury was found to have funk into the ball, the fpirit 
thermometer Ihewing at that time that the mixture was rather 
above the point of freezing, whereas before it had been below 
it. It appears, therefore, that the quickfilver in the thermo- 
meter, after having defended to - 44°*, froze in the tube, 
and fuck there ; but, being by fome means loofened, funk in- 
fantly to - 92% and again fuck tight at -95% till at laf the 
mixture riling above the freezing point, the quickfilver in the 
tube melted, and funk into the ball, to fupply the vacuum 
formed there by the frozen quickfilver. A fimilar accident of 
the quickfilver freezing in the tube of the thermometer, and 
f lcking there, and then melting and finking into the ball as 
the weather grew warmer, has been found by Dr. blagden to 
have 
