CONDUCTORS. 
- bottom of the veffel, the are coal of hot water. which 
e frit in contact wit are coole see are rendered 
fituation. 
of the above- ee motion only tbat heat ts ; propagated 
through fluids, and not otherwife.- This con nclufion was no 
a publifhed to. oa (cientifi world, than it was oppofed 
able manner a very ae philofophers. Sce. Dal- 
pee 8 paper. ae . Journ. vol.iv. p.75. Traill’s cea ibid. 
1805, p.133: and Murray? ’s gees r, ibid. v rom 
in the firft place we fhall flate 
- Into a glafs cylindrical veffel water was p 
eovered the bulb of a thermometer 5 its temperature was 40°, 
air of the room. 
Ta 
and the cord was flowly w 
was thus avoided. -In the cone or a minute the thermome> 
ter began to rife flowly ; in five minutes from the’ commence- 
of the experiment, it had rifen 4°, in ten minutes 63°, 
a aes minutes 8°. It then became ftationary, a con- 
can fo for feven reali oe it oie aaa to fal. s de- 
{cent was flow. This experiment was repeated w hot 
fie 
metallic ball (inftead of oil) immed in the water bore the 
effe&. 
thermometer, and it was attende a fimilar 
From thefe refults the ere “ight feem _ that: 
tin 
the fluid muit poflefs a ea Yet this is ren- 
dered doubtful by, the c umftance, ae in all experiments 
of this kind, a quantity sr alone muft be conveyed by the 
fides of the vefle rder a avoid this fource of error, 
Mr. Murray ats cel a veflel of ice. 
be ufed in this cafe, becaufe ae fluid a from 40° to 
32°; therefore oii and mercury were u 
A quantity of almond oil was poured i inte the ice ak 
foa as to cover the bulb of the thermometer a a of an 
of = e experiment, + the the 
it had rifen o 322°, in three minutes to 
s to 264°, infeven minutes to 374° 
ning o 
a minute anda net 
2°, in five min 
342 
this a it pean Gee. having rifen 53° in feven mi- 
mper 
jute “he temperature of the water in the cup had in this 
time "fallen to 96°. The thermometer, after remaining {ta- 
tionary at 373° for fix minutes, began to 
tinued to defcend at the rate nearly of a degree in a-minute 
and a half, till it ae to 32°. The ex ‘Seed as re- 
peated with this variation, wiz. that the thermometer was 
placed face fo that half an inch of oil foal. over its ae 
[t was alfo repeated with mercury inftead of oil. But 
ann cafes the refults were fimilar to that of the firft peeees 
municate any temper ratu 
with it, and oe aly it. could not contribute in the 
Vou. TX. 
But water could not. 
above experiment’ to raife the thermometer above that tem- 
perature. Caloric does not radiate through tranfparent 
fluids; and it cannot even be fuppofed capable of pafling by 
cur 
much more ane ai in the o 
Dr. Traill’s experiments for Taies the conducting 
asia of divers ml were performed in the following 
mann 
of wood, having its 
two.: It basa a movea le. wooden cope cover, perforated with 
a hole i in its centre, a a little more than an inch in diameter, into 
w iron cylinder, of one inch in diameter, cou 
hole perforating the cylinder near its bottom. 
mometer is bent toa right angle, fo that its bulb and part of 
its ftem lie in the axis of the wooden cylinder. 
‘{hape was preferred, becaufe the ries could be little affeted- 
by the caloric tran{mitted by the fides of the veffel, till after 
he bulb was agted on by the caloric of the ir ron bar. 
ariety h this aaa 
n the following ‘manner: ‘Lhe temperature of the roo 
67°, Fahren. therm. ; during the _ a ore 
t 
vas bet: 211° a 
iron was fuffered. to ‘remain, at each eerie for fifteen 
all the 
a 
“g 
& 
Fs] 
ide when in its Lea 
and the iron was drawn out of t 
. by means of the attached ftring, and inftantly let down 
thro the hole of the . The time the thermometer 
took to rife enough ° (viz. from 6 was accu- 
rately marked. by means of a ftop- nd the refults 
Pp hy 
e experiments on feveral fluids, are exhibited in the. 
folowing table. 
Liquids.’ 13 
y 
D 
- : . 7 L5 
Cow-milk 7 - - “ 25) 
Proof {pirit " - 8 nearly 
Alcohol, Lond. Pharmac. - 10 45 
Prag oliveoil -- . - - 9 50 
M 9 15} 
Seite of fu Iphate een iron, Salt ti. Wa — 541 8 
Saturated {olution of fulphate of alumine 9 140) 
Saturated fc men of me ta = fed i 6 30) 
qua pot on 8 A5F 
Saturated foluticn of falphate oo Zan but 
¢ liqui 1id not touching the iron cylinder, | Ke) 20 
by <i t. of an inch, or nearly fo 
3 A “cc tf 
