2 6a Dr. blagpen's Hijlory of 
■ 
funk the qulckfilver in his thermometer to 110%. and confe- 
quently froze it in part. He then interrupted the experiment 
to try the cold of his frigorific mixture by a (pint thermometer, 
and found it nearly as great as Mr. hutchins had ever pro- 
duced at Hudfon’s Bay, that is, about equal to -45° of a. 
ftandurd mercurial thermometer- 
PART II. 
NO other experiments have been inftituted, as far as hath 
come to my knowledge, for the purpofe of rendering quick- 
ill ver iolid by frigorific mixtures ; therefore I now proceed to a 
new fcries of facte, which ferve partly to confirm the former, 
and partly to (hew their application. Though the congelation 
of mercury, ab ft rafted ly coniidered, mnft be allowed to form 
a very curious and important epochs in the hiftory of that me- 
tal, yet it is as having a reference to thermometers, by teach- 
ing us what dependence can be placed upon thole inftruments, 
fixing our ideas with regard to the different diminutions of heat, 
and enabling us to form a jufter eftimate of climates, that it 
chiefly becomes interefting to the human race. The fubfequcnt 
part of this narrative will demonftrate, that quickfilver has. 
very frequently become folid by natural cold ; that in a few in- 
ftances the effect was fo palpable and obvious as to ftrike with 
immediate conviction ; but that in moft it has never been 
even fulpe&ed till the prefen t time, the ftrange appear- 
ances which often occurred being imputed by the obfcrvers to 
