146 ESSAYS AND OBSERVATIONS 



When I firft read the experiments of M. de 

 Miaran in the place referred to, I fufpefted, 

 that water, and perhaps other fluids, in eva- 

 porating, produced, or, as the phrafe is, gene- 

 rated fome degree of cold. The above ex- 

 periment of my Pupil confirmed my fufpi- 

 cion, and engaged me to verify it by a variety 

 of new trials. 



I began by repeating the experiment with 

 fpirit of wine ; and found, when I had taken 

 the utmoft care to have the fpirit exadtly of 

 the temperature of the air, that 'conftantly 

 however, upon taking the thermometer out 

 of the fpirit, the mercury funk feveral de- 

 grees, and indeed continued to fink fo long 

 as the ball of the thermometer continued wet 

 with the fpirit of wine. I found alfo, when 

 the ball began to dry, and the mercury to 

 rife again in the ftem of the thermometer, 

 that, if the ball was again dipped into the 

 fpirit and immediately taken out, the mer- 

 cury in the thermometer might be again 

 obferved to fink, and that thus, by repeated 

 dippings, the cold produced might be ren- 

 dered very remarkable. The cold produced 

 was alfo obferved to be ftill greater, when, 

 between each dipping,- the thermometer was 



moved 



