S^ Fujmn tflct under JVattr. 



TJy the rsfults of thefc experiments, and their corrcfpondence with each other, the extra- 

 ordinary fa£t is cftabliflied, that boiling water docs not fufe more water while (landing on 

 its furface in a given time, than v/ater at the temperature of 41°, or only nine degrees 

 above freezing. 



Inilced, as the Count obfervcs, there is reafon to conclude that it does not thaw fo much. 

 For the quantity melted in ten minutes by the liot water was 152 grains : and in the expe- 

 riments with the cold water the quantity was 189^- grains. He was too much inter- 

 cfted in thefe refearches to leave this anomaly unexamined. It remained to be afcertaincd, 

 whether the latter experiments were not affeded, as well as thofe with hot water, by the 

 agitation of the water in pouring in, and to what extent.; and alfo how far the aftion of the 

 external air, by cooling the outer part of the cylinder of heated water, and caufing it to dc- 

 fcend, might impede the rifing currents of cooled and expanded water from the furface of 

 the ice. This lafl object was numerically determined by clothing the jar with cotton wool 

 in fome experiments, by furrounding it totally with ice and water in others, and comparing 

 thefe refults with fuch as were afforded when all the part of the jar above the ice had been 

 left expofcd to the atmofphere. Tor thefe numbers, the judicious precautions of experi- 

 ment, and the comp.irative remarks upon them, I muft again refer the philofopher to the 

 Treatife itfelf, which every one who wifhes to invefligate the fubjed ftill farther, to repeat 

 the experiments, or to draw more extcnfive theoretical inferences from them, muft necef- 

 iarily confult. The concluding Table, drawn from the others which precede, is as follows : 



Ice melted in 30 min. 



In the experiments .n which the part-J With boiling hot water - - . ssgi 



of the jar occupied by the water was I 



r , J .. .1 • I >VVith water at the temperature 61" - 616 



expofed uncovered to the air ; then at | 1 v. «. u^u 



gjo. j With water at the temperature 41° - 574 



In .the experiments in which the part "J -yyifj^ foiling hot water - . . 399^ 



of the jar occupied by the water was ( ,,,. , , , 



■" . > With water at the temperature 01° - 661 



furrounded by pounded ice and water, j 



J , ., .. » J With water at the temperature 41° - C42 



and confequently was at 320. J it jt- 



The Count confiders thefe experiments as the moft unqueftionable proof that water is a 

 perfcd mn-conduBor ofhciit, and that heat is propagated in it only in confcquence of the 

 motions which the heat occafions in the infulated and folitary particles of that fluid. He 

 remarks, that this difcovery alTords an infight into the nature of the mechanical procefs 

 which takes place in chemical folutions ; and he thinks that it will enable us to account in 

 a fatisfaclory manner for all the various phenomena of chemical affinity, vegetation, and 

 perhaps all the other motions among the inanimate bodies on the furface of the globe. 



But without dwelling upon thefc circumftunces, lefs immediately deducible from the na- 

 ture of the communication of heat through water, the author haftens to apply his difcove- 

 ries to the great operations which are regulated and performed on the furface of the globe 

 by virtue of its moft imperfedl conducing power, and the law of its expanfion and con- 

 traftion, from the changes of temperature. This fubjeft occupies the third and con- 

 cluding chapter of his eflay. I fliall give the fubftancc as nearly in the words of the au- 

 thor as the purpofes of abridgment will allow. 



Thougli 



