lyz ESSAYS and OBSERVATIONS 



ter, and found it produced a fenfible degree 

 of cold, and feemlngly a greater^ than water 

 alone would have done. I need not here 

 obferve, that the mixture I ufed was ftill a 

 very acid liquor, only fo much faturated 

 \irith water, that it would not now attradt any 

 from the air. Whether it would not have 

 had the fame effed, tho' lefs diluted, I have 

 not had time to examine. The experiment^ 

 as it ftands, tends to prove, that the heat 

 produced by acids, applied to the ball of the 

 thermometer, is owing to the mixture of 

 thefe with the water of the air ; and there- 

 fore, it is ftill very probable, that all fluids, 

 which do not immediately affedt the mixture 

 of the air, will, in evaporating, produce cold. 

 When I had proceeded thus far, I began 

 to confider, whether the cold produced in 

 the above experiments might not be the eifedt 

 of the mixture of the feveral fluids with the 

 air ; and that therefore, to a lift of cooling 

 mixtures and folutions which I was then 

 making up, I fnould now add the feveral fo- 

 tions made by the air. By one who fuppofes 

 the evaporation of fluids to depend upon the 

 adtion of the air as a menftruum, this would 

 be readily admitted j but, as I knew that 



fluids 



