} } his Thermometer with the common mercurial ones. haais 
“ difcharging the water into which haf ice is reduced. As foon 
‘as the heated body is dropped into the cage, a cover is put on, 
which goes over both that and the firft ice’ compartment; 
“which cover is itfelf a kind of fhallow veffel, filled with 
“pounded ice, with holes in the bottom for permitting the water 
from this ice to pats into the fecond compartment, all the 
liquefaétion that happens here, as well as there, being the 
effe& of the heated body only. Over the whole is placed ano- 
ther cover with pounded ice, as a defence from external 
“warmth. 
As foon as this difcovery came to my knowledge, on the 23d 
‘of February, athaw having begun three days before, after a 
‘froft which had continued with very little intermiffion from: 
the 24th of December, I colleted a quantity of ice, and ftored 
“it up in a large cafk ima cellar. 
I thought it neceffary to fatisfy myfelf in the firft place, by 
‘a€tual experiment, that ice, how cold foever it may be, comes 
up to the freezing point through its whole mafs before it be- 
gins to liquefy on the furface. For this purpofe I cooled a large 
fragment of ice, by a freezing mixture, to 17° of FaHREN- 
-HEIT’s thermometer, and then hung it up in a room whofe 
temperature was 50°. When it began to drop, tt was broken, 
‘and fome of the internal part nimbly pounded and applied to. 
the bulb of a thermometer that was cooled by a freezing mix- 
ture below 30°. The thermometer rofe to, and continued at, 
32°; being then taken out, and raifed by warmth to 40°, fome 
more of the fame ice, applied as before to the bulb, funk it 
again to 32°; fo that no doubt could remain on this fubje@. 
Apprehenfive that pounced ice, dire&ted by the authors, might 
imbibe and retain more or lefs of the water by capillary attraction, 
according to circumftances, and thereby occafion fome error in 
the refults, 1 thought it neceflary to fatisfy myfelf in this refpect 
alf{e 
