332 Dr. blagden’s Hi/lory of 
anew ; and all his pounded ice being expended, he was fortu- 
nately obliged to fubflitute fnow in its place. With this frefh 
mixture he had the fatisfaction of feeing the mercury in his 
thermometer link to — ioo°, and in fuccefiive experiments to 
- 244 0 and -352°. Surprifed at fo unexpected an event, he 
drew the inflrument out of the mixture, and carefully exa- 
mined its bulb, to fee if it had received any injury ; but he 
found it perfectly entire, and moreover perceived a much more 
unexpected phenomenon, that the quickfilver was fixed, and 
remained immoveable above 1 2 minutes. On repeating the fame 
experiment with another thermometer, graduated no lower than 
- 220°, all the mercury funk into the ball, and became folid 
as before, not beginning to re-afcend till after a fill longer 
interval of time. 
From thefe appearances the profeflor very jufly concluded, 
that the quickfilver in both infruments had been fixed or 
frozen by the cold ; but as the evidence was not yet complete, 
he only ventured to propofe the congelation of mercury as a 
probable truth , at the next meeting of the Academy held three 
days afterwards ; and in the mean time was making prepara- 
tions to acquire more palpable proofs of the faCt. The ther- 
mometers ordered with this view were not ready till the 25th 
of December O. S. when, in company with the celebrated 
iEPiNus, Profeflor of Phvfics, he performed the experiment with 
iimilar materials, and as foon as he found the quickfilver im- 
moveable, broke the bulb of his thermometer. Now all his 
doubts were removed ; he obtained a folid fhining metallic mafs, 
which extended under the frokes of a pefle, in hardnefs 
rather inferior to lead, and yielding a dull dead found like that 
metal. Profeflor a:pinus was occupied at the fame time in 
Iimilar experiments, employing both thermometers and Ample 
tubes 
