ithe Nature and ufeful Properties of Salt. 61 
The peculiar Excellence of thefe Salts 
for the Prefervation of Flefh, Fifh, &c. is 
too well known to need Defcription; and 
their other extraordinary Virtues, when pre¬ 
pared in different Ways, are too many to be 
mentioned here. Glauber afferts, that com¬ 
mon Salt is the mo ft ufeftil and moft ex¬ 
cellent of all the reft, being the Princi¬ 
ple whence all other Salts, either known 
or unknown, are chiefly derived, and may 1 
by Art be produced. By a little Labour and 
Fire, and the Addition of fome metallic 
Sulphur, it may, he fays, be converted into 
Alum or Vitriol ; by Fire, Air, and Su-lphur* 
into Salt-Petre ; by the Help of a fiercer 
Fire, into an alkalious Salt, and by deftroy- 
ing its Acridity, into a Salt fit for enriching 
Land, and extremely ferviceable to fandy 
and barren Soils *. 
Common Salt diffolved in fharp Vinegar,- 
and a Drop thereof a little heated, fhoots' 
fome pretty Configurations from the Edges,* 
and affords Cryftals of the Figures juft now 
defcribed, extremely clear and beautiful, 
though fmaller than ufual. Thefe frequently 
are joined together with a curious Variety 
©f Compofition, which the Cryftals of the 
fame Salt diffolved in Water never exhibit p 
for they commonly form feparate and dif- 
pofed at Diftances from each other. 
* Vid. De Naf, Salium, Amftel, p. 49- 
6 Diffolved 
