15© ESSAYS AND OBSERVATIONS 



feemed to me to occafion the greateft finking 

 of the thermometer, and the reft follow in 

 order as they feemed to occafion lefs and 

 iefs. 



From the above enumeration I imagine it 

 will appear, that the power of evaporating 

 fluids in producing cold, is nearly according 

 to the degree of volatility in each. If to this 

 we join the confideration, that the cold is 

 made greater by whatever haftens the eva- 

 poration, and particularly, that the finking of 

 the thermometer is greater as the air in which 

 the experiment is made is warmer, if dry at 

 the fame time; I think we may now con- 

 clude, that the cold produced is the effeSi of 

 evaporation. , 



I did not think it necefiary to diverfify my 

 experiments further by examining a great 

 many fluids, which are manifeftly of a like 

 nature with thefe above-mentioned. I pre- 

 fume pretty confidently, that the feveral fpi- 

 rituous, watery, and oily fluids, akin to thefe 

 already tried, will be found all of them to 

 have fimilar effeds. And, confidering tiow 

 many fluids thefe claflTes comprehend, and 

 that, in thefe already tried, the cold produced 

 feems to depend more on the volatility of the 



aggregate 



