148 ESSAYS AND OBSERVATIONS 



is not proper to employ a thermometer in- 

 clofed in a glafs tube ; and it is neceffary to 

 employ one having a fmall ball, which may 

 render it more fenfible. But, as a frnall ball 

 occaiions the divifions of the fcale to be the 

 fmaller, a thermometer filled with quick- 

 filver is not fo proper for thefe experiments, 

 as one filled with fpirit of wine ; having at 

 the fame time both a fmall ball and a {lender 

 flem. What befl of all ihews the cold .pro- 

 duced, and is indeed, with refpedt to feveral 

 fluids, quite-neceffary, is an Air thermometer. 

 This too will be rendered more convenient 

 by having the upper part of 

 the tube bent as in the figure 

 annexed, fo that the ball / 

 may be moiftened without 

 the liquor's running down 

 upon the flem and fcale. 



I have entered into this detail for the fake of 

 thofe who" may defire to repeat my experi- 

 ments. Having now faid enough on the man- 

 ner of making them, I go on to obferve, that 

 in this way I have examined a great variety of 

 fluids. Such as. 



The 



