Experiments on the Tranfmijion tf Heat ihrcugb Fluids. <4j 



Dunt»g the whole of this experiment the amber continued perfe£lly motionlefs; con- 

 fequently there were no currents. But there muft have been currents, if the heat had 

 been communicated by the fides of the veilel ; for in that cafe the particles of the liquid 

 next the fides muft have received heat : this would have caufed them to afcend, and there 

 would have been defcending currents in the interior parts of the liquid. It is not poffible, 

 then, to fuppofe that the thermometers rofe in confequencc of caloric conducted to them 

 by the fides of the veflel. 



.3. If the thermometers had rifen in confequencc of currents of the hot liquid ftriking 

 againft them, thefe currents vi'ould have been vifible in feveral of the experiments. If the 

 fmalleft particle of oil, for inftance, had made its way through the water, it would have 

 been detected by its whitenefs. We are abfolutely certain that no fuch currents exifted in 

 the 6th experiment ; for had the fmalleft atom of the water, tinged with red cabbage, made 

 its way through the carbonate, it would have been inftantly detected by a change of colour 

 from blue to green. But no fuch change of colour took place: nay, more than fix hours 

 after the experiment, no green colour could be perceived ; but it appeared inftantly after a 

 very flight agitation. Befides, how could oil or water makes its way downwards through 

 mercury ? This fuppofition, then, rauft alfo be given up. 



4. If the cold liquid had been fo much agitated by pouring the hot liquid over it, that 

 currents of it, heated dire£tly by the hot liquid, made their way to the thermometers, thefe 

 currents muft Iiave been vifible in the 6th experiment» which was made on purpofe to 

 deleft them. Now, as the amber remained perfeftly motionlefs, even during the pouring 

 in of the hot liquid, and never moved after, it follows that no fuch currents exifted. 

 Confequently, the fourth fuppofition cannot be admitted. 



Upon the whole, then, I confider thefe experiments as proving, beybnd a doubt, that 

 water and mercury are condudlors of caloric. I have repeated them frequently, in order 

 to guard as much as poiTible againft miftakes : but I truft that others, who are interefted in 

 this fubjedl, will lake the trouble to repeat them. I may, perhaps, have overlooked fome- 

 thing, notwithftanding all my caution. If, I have, the experiments are fo eafily made,, 

 that it cannot fail to be very foon .difcovered. Whatever may be the ifliie of this in- 

 veftigation, the greateft part of the merit belongs exclufively to Count Rumford. My 

 experiments were made merely in xonfequence of his, and I availed tajfelf of the con- 

 trivances which he himfelf had fuggefted. n ' , 



To fee whether fulphuric acid be a condudor of caloric, I made the following experiment: 

 a EXPERIMENT 



