But yet in Summer time, if
your _Lixivium_ have been duly Impregnated and well Filtred after it is
quite cold, it will for some dayes (perhaps much longer than I had occasion
to try) retain Antimony enough to exhibit, upon the Affusion of the
Corrosive Oyl, as much of a good Yellow Substance as is necessary to
satisfie the Beholders of the Possibility of the Experiment.

_Reflections upon the XL. Experiment Compared with the X. and XX._

The Knowledge of the Distinction of Salts which we have propos'd, whereby
they are discriminated into _Acid, Volatile,_ or _Salfuginous_ (if I may
for Distinction sake so call the Fugitive Salts of Animal Substances) and
_fix'd_ or _Alcalizate_, may possibly (by that little part which we have
already deliver'd, of what we could say of its Applicableness) appear of so
much Use in Natural Philosophy (especially in the Practick part of it) that
I doubt not but it will be no Unwelcome Corollary of the Preceding
Experiment, if by the help of it I teach you to distinguish, which of those
Salts is Predominant in Chymical Liquors, as well as whether any of them be
so or not. For though in our Notes upon the X. and XX. Experiments I have
shown you a way by means of the Tincture of _Lignum Nephriticum_, or of
Syrrup of Violets, to discover whether a propounded Salt be Acid or not,
yet you can thereby only find in general that such and such Salts belong
not to the Tribe of Acids, but cannot determine whether they belong to the
Tribe of Urinous Salts (under which for distinction sake I comprehend all
those Volatile Salts of Animal or other Substances that are contrary to
Acids) or to that of Alcalies. For as well the one as the other of these
Salino-Sulphurous Salts will restore the Caeruleous Colour to the Tincture
of _Lignum Nephriticum_, and turn that of Syrrup of Violets into Green.
Wherefore this XL. Experiment does opportunely supply the deficiency of
those. For being sollicitous to find out some ready wayes of discriminating
the Tribes of Chymical Salts, I found that all those I thought fit to make
Tryal of, would, if they were of a Lixiviate Nature, make with Sublimate
dissolv'd in Fair Water an _Orange Tawny_ Precipitate; whereas if they were
of an Urinous Nature the Precipitate would be _White_ and Milky. So that
having alwayes by me some Syrrup of Violets and some Solution of Sublimate,
I can by the help of the first of those Liquors discover in a trice,
whether the propounded Salt or Sal