1819.] and on the Laws of the Communication of Heat. 247 
Lastly, when thesurrounding medium is 80°, we have 
V = 3-754 (a' — 1) 
Excesses of temp. or Values of V ob- Values of V cal- 
values of ¢, served. culated. 
ds ese dete 5. 3; {8 00) bajo LY. 1s \ ery 13°52° 
EEE eer DO Mee tiarazs*¢ fier. apes 11-69 
BM slice avs eepigabl SRA ray in 05 0 8°98 
BI aK i aware rae (Lot a a 7°18 
ae TC) Oe ea - 561 
TOBA. 0s. «ictal sieiprainrs ANE Hg Ais colin: 0:0 \n) oysi-n,e 4°30 
LE ie Sie Ena? a | ARS Mae 3°16 
SEELEY eee ake RN rar Fran sodas: ange’ "28 
The remarkable agreement of the regults of calculation and 
observation leaves no doubt of the accuracy of the law to which 
we have been led. Without stopping at the consequences 
which may be deduced from it, and upon which we shall return 
immediately, let us examine the series of the velocity of cooling 
when the bulb of the thermometer is covered with silver. When 
these series were calculated, we. immediately perceived, on 
comparing them with the analogous series when the thermometer 
was naked, that the velocities of cooling in these last, for the 
same temperature of the surrounding medium and the same 
excess of temperature of the body, were proportional to the cor- 
responding velocities of cooling when the bulb was silvered. 
The formula found above, then, will apply also in the case of 
silver, ; preserving to a the same value, and diminishing m 
roperly. : 
a ur first observation on the cooling of the silvered thermo- 
»meter was made, 6 being equal to 20°. We found that it was 
necessary to suppose m = 0°357, and consequently ma? = 0°416. 
Hence 
V = 0-416 (at — 1) 
Excesses of temp. or Values of V ob- Values of V cal- 
values of t. served. culated. 
2a cal WHE Ries, ERE RN Re kee oie ly a a eee aL 
FCN aie Deer aa Citing gaye LSS NE A SB a i Pk TES 
7 aA Dag ey Yn a NB EON og ah oy Son oh PAM is Be 
“gS B RSS IAS CE 1 oe ile tas MASSES IAS 
BAM EOP PBI Oy ot Paracel at's sas n, ethate 1°50 
BRT sak, wlee stata nate BG OF ott as we 1:23 
MEME 5g enita a nok Bc 0 aia ne ee oe. 1:00 
EASE Cae ) Eat RA SAMA So 0-80 
RAAB al OR Gre nde ate ooh me 0°62 
Ne, ss i d'ciwc'g tae OO asi sia «6, geek 0°48 
TN sso ss on cle wo Tie OAS PA ty OD 
Sa “6. WOE. b wane ann aee nent 
MTT dss > oct ct OU TONG os ot asada ener LO 
20 oe sees ecee ees 0:07 etooereeeene 0:07 
