PHYSICAL anp LITERARY. 187 
' IMacrtninc thatT perceived fome re- 
femblance between the properties of mag- 
néfia and thofe of alkalis, I was led to try 
what change this fubftance would foffer 
from the addition of quick-lime, which 
alters in fuch a peculiar manner the alka- 
line falts. 
TwENTY feven grains of magrefia in 
fine powder were mixed with eighteen 
ounces of lime-water in a flafk, which was 
corked clofe and fhaken frequently for 
four days. During this time, | frequent: 
ly dipp’d into it little bits of paper, which 
were coloured with the juice of violets ; 
and thefe became green as foon as they 
touched the water, until the fourth day, 
when their colour did not feem to be alter- 
ed. The water being now poured off, was 
intirely infipid, and agreed in every che- 
mical trial with pure water. The pow- 
der, after being perfeCtly well dried, weigh- 
ed thirty feven grains. It did not diffulve 
intirédly in fpirit of vitriol ; but, after a 
brifk effervefcence, part of it fubfided in | 
' the fame manner as the calcarious earths, 
~ ewhen mixed with this acid. 
WHEN 
