iipan Ice, thaws it move fpeetlily than Hit IVafei: 



5(>5 



melted In pouring the hot lualer into the jar, there will remain 478 grains for the quantity 

 melted in the ordinary courfe of the procefs in 30 minutes, which gives 159 grains for the 

 quantity melted in ten minutes; which differs very little from the refult of the foregoing 

 computation, by which it appeared to be= 154 grains. This difference, however, fmall as it 

 is, is fufficient to prove an important faft, namely, that the effects produced by the motion 

 into which the hot water had been thrown on being poured into the jar, had not ceafed 

 entirely in lo minutes, or when an end was put to the 5th experiment. We fliall therefore 

 come nearer the truth, if, in our endeavours to difcover the quantity of ice melted in any 

 given time in the ordinary courfe of the experiment, we found our computation on the 

 refults of the two experiments. No. 26 and No. 27. 



In the latter of thefe experiments 3200 grains of ice were melted in 180 minutes, and in 

 the former 914 grains were melted in 30 minutes. If, therefore, from 3200 grains, th? 

 quantity melted in 180 minutes, we take the quantity melted in the firft 30 minutes = 914 

 grains, there will remain 22B6 grains for the quantity melted in the fucceeding 150 minutes, 

 and this gives 152 grains for the quantity melted in 60 minutes. By the former compu- 

 tation it turned out to be 154 grains. 



But if 152 grains of ice is the quantity melted in 10 minutes In the ordinary courfe of the 

 procefs, three times that quantity or 456 grains only would have been melted in this man- 

 ner in the 30 minutes during which the 26th experiment laded ; and deducting this quan- 

 tity from 914 grains, the quantity aftually melted in that experiment, the remainder 458 

 grains flicws how much mult hate been melted in the pouring the hot water on the ice, 

 or in confequence of the motion into which the water was thrown in the performance of 

 that operation. By the preceding computation this quantity turned out to be 426 grains. 



From the refult of thefe computations the Count thinks we may fafely conclude, that in 

 the ordinary courfe of the experiments not more than 152 grains of ice were melted by the 

 hot water in ten minutes. 



He then proceeds to give an account of feveral experiments, in which the water em- 

 ployed to melt the ice was at a much lower temperature. 



The previous congelation of water in the jar to the depth of four inches, the fubfequent 

 reduction to the temperature of 32'^ by the external contaft of ice and water, and the 

 weighing of the whole jar and ice contained therein, were performed as in the former ex- 

 periments. The jar, which had been w iped with a dry cold napkin before weighing, was 

 then replaced in the ice and water to the depth of its internal contents of ice. The quan- 

 tity of 73^ ounces troy of water at the temperature of 41 " (which was alfo that of the 

 room) was then poured in with the fame precaution, of tlic wooden tube, difli, t^c. as be- 

 fore. The refults of a fet of experiments were thefe : 



