PHYSICAL AND LITERARY. 201 



the alkali, which is uniformly difFufed thro' 

 every part of the liquor. 



The above ley was found upon trial to be 

 faturated by acids without the leaft effervef- 

 cence or diminution of weight. 



It was no\v proper to examine whether 

 the alkali fufFered any lofs in becoming 

 cauftic, which I propofed to attempt by af- 

 certaining the ftrength of the ley, or the 

 quantity of fait which a given portion of it 

 contained j from which by computation 

 fome imperfect knowledge might be obtained 

 of the quantity of cauftic produced from the 

 eighteen ounces of mild fait. 



I therefore evaporated fome of my ley, 

 but; foon perceived that no certain judgment 

 could be formed of its ftrength in this way, 

 bfecaufe it always abforbed a coniiderable 

 quantity of air during the evaporation, and 

 the dried fait made a pretty brifk eifervef- 

 cence with acids, fo that the ley appeared 

 ftrong«;r than it really was ; and yet, upon 

 proceeding in the eftimate from this rudq 

 and unfair trial, it appeared that the fait had 

 loft above a fixth in becoming cauftic, and 

 the quantity of acid faturated by two drams of 



Vol. it C c it 



