379 
IN THE CURE OF THE STONE. 
from water during its ebullition with quick-lime, is intirely devoid 
of the virtues of lime, and fcarcely differs from common water. 
Yet, upon adding one part white-wine vinegar to ten or twelve 
parts ftone lime-water, after feveral days, I perceived fome faline 
concretions adhering to the fides of the glafs : thefe tailed not un¬ 
like fea-falt, but fweeter, and, no doubt, proceeded from the acid 
fait of the vinegar rendered neutral by the lime-water. Having in- 
fufed a fragment of B in fome oilier lime-water, made with fhells 
that had lain fifteen hours after being taken from the fire, I was 
furprifed to obferve, in three or four days, a prodigious number 
of fin all pointed chryftallifations, like fine needles, about the fixth 
part of an inch long, darting as it were into its furface, and giving 
it fome what the appearance of a hedgehog. But I am apt to think, 
that thefe did not proceed from the lime-water, but • the fea-falt; 
with which the oiller-fhells, even after calcination, fo much a- 
bound *. And accordingly I have fince often obferved the fame 
faline chryftallifations, tho’ not fo remarkable, produced by lime- 
water made with oifter-ftiells newly got from the fea ; although, as 
far as I remember, never from ftone lime-water, nor that made 
with calcined fhells, which, by being long expofed to the weather, 
had been intirely deprived of their fea-falt. We are told indeed, 
that Mr Leeuwenhoek difcovered, by his microfcopes, in lime-water, 
a great number of faline rigid particles f. But whether his ima¬ 
gination aftifted him herein, or whether he did not rather want to 
difcover a fimilitude betwixt this water and that got off burnt cal¬ 
culi, and the tophaceous matter which fometimes ilfues from the 
joints of gouty perlons ; or whether there really are fueh faline par¬ 
ticles, I will not take upon me to determine : For altho’ it has been 
the general opinion of the mod eminent chymifts, that no fait 
could be procured from quick-lime ; yet, of late, Mr Du Fay J 
pretends to have extra&ed a fait from lime-water, and has given an 
account at large of the way in which this may be done. But, fince 
his fait is of the neutral kind, and does not feem to be poffelfed of 
B b b 2 any 
* See No 67. below. f Mufgrave de arthritide, cap. 9. § 4, 
$ Mémoires de l’Acad. des fciences 1724.