the vertues of their concretes; and consequently very differing
Operations. So we find the _Alkali_ of Wormwood much commended in
distempers of the stomach; that of Eyebright for those that have a
weak sight; and that of _Guaiacum_ (of which a great Quantity yields
but a very little salt) is not only much commended in Venereal
Diseases, but is believed to have a peculiar purgative vertue, which
yet I have not had occasion to try. And though, I confess, I have long
thought, that these _Alkalizate_ salts are, for the most part, very
neer of kin, and retain very little of the properties of the
Concretes whence they were separated; Yet being minded to Observe
watchfully whether I could meet with any Exceptions to this General
Observation, I observ'd at the Glasse-house, that sometimes the Metal
(as the Workmen call it) or Masse of colliquated Ingredients, which by
Blowing they fashion into Vessels of divers shapes, did sometimes
prove of a very differing colour, and a somewhat differing Texture,
from what was usuall. And having enquired whether the cause of such
Accidents might not be derived from the peculiar Nature of the fixt
salt employ'd to bring the sand to fusion, I found that the knowingst
Workmen imputed these Mis-adventures to the Ashes, of [Errata: Ashes
off] some certain kind of Wood, as having observ'd the ignobler kind
of Glass I lately mention'd to be frequently produc'd when they had
employ'd such sorts of Ashes which therefore they scruple to make use
of, if they took notice of them beforehand. I remember also, that an
Industrious Man of my acquaintance having bought a vast quantity of
Tobacco stalks to make a fixt Salt with, I had the Curiosity to go see
whether that Exotick Plant, which so much abounds in volatile salt,
would afford a peculiar kind of _Alcali_; and I was pleas'd to find
that in the _Lixivium_ of it, it was not necessary, as is usual, to
evaporate all the Liquor, that there might be obtain'd a Saline Calx,
consisting like lime quench'd in the Air of a heap of little
Corpuscles of unregarded shapes; but the fixt salt shot into figur'd
Crystal, almost as Nitre or _Sal-armoniack_ and other uncalcin'd salts
are wont to do; And I further remember that I have observ'd in the
fixt Salt of Urine, brought by depuration to be very white, a tast not
so unlike to that of common salt, and very differing from the wonted
caustick Lixiviate tast of other salts made by Incineration. But
because the Instances I have alledg'd of the Difference of
_Alcalizate_ salt are but few, and therefore I am still inclin'd to
think, that most Chymists and many Physitians do, inconsideratly
enough and without Warrant from Experience, ascribe the Vertues of the
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