~ 
352 - Count Rumford on ihe . 
From thefe refults the ingenious author concludes, and 
certainly his experiments juttify the conclufion, that boiling- 
hot water is not capable of melting more ice, when /ianding 
en its furface, than an equal quantity of water at the tem- 
perature of 41°, or when only g degrees above freezing-—a 
fa&t which proves that water is a perfeét non-conduétor of 
heat, and that heat is propagated in it ondy in confequence 
of the motions which ‘the heat occafions in the infulated 
and folitary particles of that fluid, by altering their fpecific 
gravities. He here obferves, in a note, that the infight 
which this difeovery gives us in regard to the nature of the 
-mechanical procefs which takes place in chemical folutions, 
is too evident to require illuftration. 
The author having frequently obferved, when freezing 
water in one of his jars into a cake of ice, by placing the 
jar ina freezing mixture, that the water in the axis of the 
jar, which was lateft in freezing, being comprefled by the 
expanfion of the ice round it, was always forced upwards, 
and formed a pointed projeGtion of ice in the form of a 
nipple, which was fometunes above 4 inch high, was led by 
the circumftance to make another experiment, which proved 
oil to be alfo a non-conductor of heat. 
Into a jar (fee fig. 4) containing a cake of ice @ of the 
form above defcribed, fome fine olive oil, previoufly cooled 
to'32°, was poured till it ftood (at 4) 3 inches above the 
furface of the ice, A folid cylinder of iron ¢ 1} inch in 
diameter, and 12 inches high, and a paper fheath over it, 
the lower end of which projected = of an inch paft the 
cylinder, fo contrived as to be fufpended over the centre of 
the ice by means of the hook d and the wire e, faftened to 
the ceiling of the room, being heated to 210° in. boiling 
water, was immerfed in the oil fo deep that the middle of 
the flat furface of the lower end of the, hot. iron. was only: 
TO 
diftant from the conical projection of the ice,7, of an inch. 
Had any heat di efiraded, a portion of the ice would have 
been 
