PHYSICAL AND LITERARY. 155 



'/^'I'u^fz^o produces -a greater degree of cold 

 than the evaporation of the fame in the air. 



Satisfied of this, I have tried alfo fome 

 other fluids, as the qyick-Hme fpirit of fal. 

 ammoniac, and the two kinds of aether. 

 VefTels containing thefe With a thermometer 

 immerfed in the hquor, but feparately and at 

 different times, were fet under the receiver. 

 With regard to the different fluids, the phce- 

 nomena were much the fame. Upon ex- 

 haufting the receiver, the fluid gave out a 

 great quantity of elafliic air ; and ^while this 

 -happened, the mercury in the immerfed 

 -thermometer funk very faff and to a great 

 •length. In our trials, it generally funk below 

 the fcale applied fo that we could not 

 meafure exa£lly how far. In one experi- 

 ment before exhaufting the receiver, the 

 thermometer had fl:ood at 50 degrees, and, 

 after exhaufl:ing, we could judge very cer- 

 tainly that it funk to below 20. In another 

 experiment made with the nitrous aether, 

 when the heat of the air was about 53 de- 

 grees, we fet the veffel containing the aether 

 in another a little larger containing water. 

 Upon exhaufting the receiver, and the veffel's 

 remaining for a few minutes in 'vacuo^ we 



found 



