202 ESSAYS AND OBSERVATIONS 



it was to the quantity of acid faturated by two- 

 drams of fait of tartar, nearly as fix to five. 



These experiments are therefore agreeable 

 to that part of the fecond propofition which 

 relates to the cauftic alkali. 



Upon farther examining what changes the 

 alkali had undergone, I found that the ley 

 gave only an exceeding faint milky hue ta 

 hme-water j becaufe the cauftic alkali wants 

 that air by which fait of tartar precipitates 

 the lime. When a few ounces of it were 

 expofed in an open (hallow vefTel for four 

 and twenty hours, it imbibed a fmall quan- 

 tity of air, and made a flight effervefcence 

 with acids. After a fortnight's expofure in 

 the fame manner, it became entirely mild, 

 effervefced as violently with acids, and had 

 the fame effed upon lime-water as a folution 

 of an ordinary alkali. It likeways agrees 

 with lime-water in this refpeft, that it may 

 be kept in clofe vefTels, or even in bottles 

 which are but flightly covered, for a confide- 

 rable time, without abforbing a fenfible quan- 

 tity of air. 



In order to know how much lime it con- 

 tained, I evaporated ten ounces in a fmall 

 . . filver 



