T 2 ] 
to ail others j that extravagant Fluid , as Mr. Boyle 
calls it, being mod eafily l'ufceptible both, of Heat 
and Cold, and, when well purified, not liable to be 
obdruded in itis Motion. 
I had, by fome Years Experience, found both the 
Excellence of them, and the Neceffity of keeping 
them in the open fhaded Air, before I met with the 
learned and curious Etlays Medical and Phiiofophi- 
cal of Dr. George Martine , in which he fo much 
recommends their Ufe ; and it was no final 1 Satif- 
fadion to me, to find that Gentleman had proved, 
by Experiments, that Quickfilver both heats and cools 
fafter than any Liquor we know# fader, 1 am dire 
(lays he), than Water, Oil, or even Spirit of Wine, 
and never freezes, by any Degree of Cold hitherto 
obferved. 
Might I be indulged the Liberty, I would embrace 
this Opportunity of inviting fuch Gentlemen, as at- 
tend to this Branch of Natural Philofophy, to con- 
fider what Dr. Martine has faid to* recommend the 
Ufe of Thermometers made with Quickfilver, and 
to place them in the open Air, guarded from the 
Sun’s Rays? which, fome Obfervations I made, and 
did my felffthe Honour to lay before the Royal Society 
formerly*, may ferve to fhew the Necedity of ■, efpe- 
ciaily a more remarkable one, lately made, which I 
fhall fubj-oin hereto. 
There is another Particular of great Importance, 
which I fear we may rather wifh than hope to fee 
made a general Pradice, recommended by the fame 
Gentleman# thatisj the condruding all Thermome- 
ters with one Scale But if this may not be expeded, 
* • - certainly 
• See Pbil. Tran/. N<\ 484, p. 613. 
