238 Historical Review of Experiments 



known experiment of the cold body and the speaking- 

 tube (and this was before the instrument necessary for 

 the purpose had been invented), and thus to terminate 

 our (in all respects very friendly) controversy on the 

 reality of caloric. 



This experiment was afterwards performed in the 

 physical cabinet of the National Institute in the pres- 

 ence of Laplace, Bertholet, and Charles. The result 

 was precisely as I had predicted. 



On the 28th Ventose of the year 12 (the I9th of 

 March, 1804) I presented to the Mathematical and 

 Physical Class of the National Institute my first me- 

 moir, in which I described my thermoscope and a few 

 of the discoveries that I had made with the help of 

 this instrument. 



On the fth Germinal (26th of March, 1804) I pre- 

 sented to the same Class a second memoir, in which I 

 sought to develop my ideas on the nature of heat, as 

 well as on the manner in which it is excited and com- 

 municated. At the same time I gave the results of cer- 

 tain experiments which I had made on the cooling of 

 warm bodies in the air. . 



On the i gth Germinal (pth of April, 1804) I pre- 

 sented to the Class a third memoir, which treated of an 

 experiment, which I had recently made in Paris, on the 

 nature of heat ; by this experiment the influence of the 

 rays emanating from cooling bodies was rendered mani- 

 fest in a manner entirely new. 



On the loth Floreal (joth of April, 1804) my fourth 

 memoir was presented to the Class. In this memoir I 

 described an experiment which I performed with two 

 flasks of equal size. One was made of glass, the other 

 of tinned iron. Both were filled with boiling water, 



