Conjectures I have about the differing Natures of the
Several Tribes of Salts, having led me to devise the Experiment, it will
not be difficult for me to give you the Chymical Reason, if I may so speak,
of the _Phaenomenon_. Having then observ'd, that _Mercury_ being dissolv'd
in Some _Menstruums_, would yield a dark Yellow Precipitate, and supposing
that, as to this, common Water, and the Salts that stick to the _Mercury_
would be equivalent to those Acid _Menstruums_, which work upon the
_Quick-silver_, upon the account of their Saline particles, I substituted a
Solution of Sublimate in fair Water, instead of a Solution of _Mercury_ in
_Aqua-fortis_, or Spirit of _Nitre_, that simple Solution being both
clearer and free from that very offensive Smell, which accompanies the
Solutions of _Mercury_ made with those other corrosive Liquors; then I
consider'd, that That, which makes the Yellow Colour, is indeed but a
Precipitate made by the means of the Oyl of Tartar, which we drop in, and
which, as _Chymists_ know, does generally precipitate Metalline Bodies
corroded by Acid Salts; so that the Colour in our case results from the
Coalition of the Mercurial particles with the Saline ones, wherewith they
were formerly associated, and with the Alcalizate particles of the Salt of
Tartar that swim up and down in the Oyl. Wherefore considering also, that
very many of the effects of Lixiviate Liquors, upon the Solutions of other
Bodies, may be destroy'd by Acid _Menstruums_, as I elsewhere more
particularly declare, I concluded, that if I chose a very potently Acid
Liquor, which by its Incisive power might undo the work of the Oyl of
Tartar, and disperse again those Particles, which the other had by
Precipitation associated, into such minute Corpuscles as were before singly
Inconspicuous, they would become Inconspicuous again, and consequently
leave the Liquor as Colourless as before the Precipitation was made.

This, as I said, _Pyrophilus_, seems to be the Chymical reason of this
Experiment, that is such a reason, as, supposing the truth of those
Chymical Notions I have elsewhere I hope evinc'd, may give such an account
of the _Phaenomena_ as Chymical Notions can supply us with; but I both here
and elsewhere make use of this way of speaking, to intimate that I am
sufficiently aware of the difference betwixt a Chymical Explication of a
_Phaenomenon_, and one that is truly Philosophical or Mechanical; as in our
present case, I tell