6 1 
Experiments upon Heat. 
water, cooled it in ice and water, as in the foregoing experi- 
ments. The results of the experiment were as may be seen in the 
following table ; and in order that it may be compared with 
those made with the same quantity of silk differently disposed 
of, I have placed those experiments by 4 :he side of it : 
Heat lost. 
Raw silk, 16 grs. 
Fine ravelings of 
taffety, 16 grs. 
Sewing silk cut 
into lengths, 
16 grs. 
Sewing silk, 
16 grs. wound 
round the bulb 
of the thermo- 
meter. 
lExp. No. 4. 
Exp. No. 14. 
Exp. No. 15 
Exp. No. 19. 
70 ° 
j 
- 
- 
6 o° 
94 " 
9 °" 
67" 
46" 
5 °° 
110 
10 6 
79 
6' 2 
40° 
*33 
128 
99 
85 
30° 
185 
172 
1 35 
121 
20° 
2 73 
246 
195 
391 
10° 
489 
427 
342 
399 
Total times. 
1284 
1169 
9 1 7 
9°4 
It is not a little remarkable, that, though the covering 
formed of sewing silk wound round the bulb of the thermome- 
ter in the 19th experiment, appeared to have so little power of 
confining the heat when the instrument was very hot, or when 
it was first plunged into the ice and water, yet afterwards, when 
the heat of the thermometer approached much nearer to that 
of the surrounding medium, its pow 7 er of confining the heat 
which remained in the bulb of the thermometer appeared to 
be even greater than that of the silk in the experiment N° 15, 
the time of cooling from 20° to io° being in the one 399", and 
