PHYSICAL anno LITERARY. 221 
"THE above ley was found upon trial to 
bi faturated by acids without the leaft ef- 
- fervefcence or diminution of weight, 
Ir was now proper to exaraine whether. 
the alkali fuffered any lofs in becoming 
cauftic, which | propofed to attempt by 
_ afcertaining the firength of the ley, or the 
quanuty of falt which a given portion of 
it contained , from which, by computa- 
tion, fome imperfect knowledge might be 
obtained of the quantity of cauftic produ- 
ced from the eighteen ounces of mild fale, 
I therefore evaporated fome of my ley ; 
but foon perceived that no certain judge- 
ment could be formed of its firength in 
this way; becaufe it always abforbed a 
confiderable quantity of air during the e- 
yaporation, and the dried falt made a 
pretty brifk effervefcence with acids, fo 
- that the ley appeared ftronger than it real~ 
ly was; and yet, upon proceeding in the 
_ eftimate from this rude and unfair trial, 
it appeared that the falt had loft above a 
fixth in becoming cauftic, and. the quan- 
ty of acid faturated by two drams of it 
os to the quantity of acid faturated by 
two 
