382 ESSAYS ann OBSERVATIONS 
the water will extract it, and continue to do 
fo, till it has taken up as much of. the lime 
as it can bear. But to this we cannot a- 
gree: -for, tho’ there is undoubtedly a cer- 
tain degree of {trength which lime-water can 
never exceed; yet, in order to communicate 
to water, this degree of f{trength, flaked 
lime may not only be infufficient, but repeat- 
ed additions of quick-lime may be neceffary; 
unlefs perhaps a very {mall proportion of wa- 
ter is poured upon it. Quick-lime, frefh from 
the fire, yields its virtues more eafily, than 
when weakened by long expofition to the air, 
or by many affufions of water: the water 
muft extract the virtues of the latter, while 
the former, by a fort of explofive force of 
its own, quickly impregnates the water. Nor 
is it to be wondered at, that quick-lime, frefh 
from the fire, fhould, at firft, impregnate 
water more ftrongly with its virtues, than it 
does afterwards. ‘This is as eafily conceived, 
as that boiling water fhould extract more of 
the virtues of tea or coffee, than cold water. 
The only difference is, that the menfruum in 
the latter cafe aéts more powerfully, while 
in the former the fubftance to be extracted 
affords 
