358 * Cotin! Ruinford én the 
chanical means, and without forming any combination with 
it whatever, merely obftru& its internal motions, it appears 
to the ingenious author, and we believe it will not be denied, 
that this proves, that heat is propagated in water a confe~ 
“quence of its internal motions ;—or, that it is tranfported or 
cartied by the particles of that liquid, and that it does not 
fpread and expand in if, as in metals and other conductors 
of heat, as has generally been imagined. . 
The fuccefs of thefe experiments encouraged the author 
to plan and execute others ftill more decifive and extremely 
interefting, Ithas been generally believed that water can- 
not be hedted in contaét. with ice: reflecting on the fubject, 
he perceived that either this muft be a miftake, or his ideas 
re{peéting the manner in which heat is\propagated in that 
fluid, erroneous. On the fuppofition that water is not a con- 
duétor of heat, according to the common acceptation of.that 
term, or that heat cannot pafs in that fluid, except when 
carried by its particles, which, being put in motion by the 
r change it occafions in their fpecific gravity, tranfports it 
from place to place, it did not appear how ice, if, inftead of 
being permitted to fwim on water, it were confined at the 
bottom of it, or any where below the furface, could affect the 
temperature of the fuperincumbent water, or prevent its 
receiving heat from other bodies : but, on the other hand, 
the ice-cold water which refults from the melting of ice 
when on the furface of that fluid, cannot but defcend by its 
gravity to the bottom of the containing veffel in an uninter- — 
rupted ftream; fo that as long as this operation is going on 
the mafs of water cannot be much heated. 
A cylindrical glafs jar 4:7 inches diameter and 14 inches 
high was nearly filled with boiling hot water. A circular, 
cake of ice ofnearly the famé diameter, 3! inches: thick, and 
weighing 1010z. was then gently put.on the furface of the 
water, In/2''58'' it wasentirely melted. tt 
A cake: of aéc of the fame form and dimenfions with the 
above was afterwards faflened down on the bottom of ‘the 
eoaend . fame 
“~y 
