y ton'd, though each of them struck apart would
yield a Pleasing Sound, yet being struck together they make but a Harsh and
troublesome Noise. But this not being so fit a place to prosecute
Speculations, I shall not insist, neither upon these Conjectures nor any
others, which the Experiment we have been mentioning may have suggested to
me. And I shall leave it to you, _Pyrophilus_, to derive what Instruction
you can from comparing together the Various ways whereby a Yellow and a
Blew can be made to Compound a Green. That which I now pretend to, being
only to shew that the first of those mention'd ways, (not to take at
present notice of the rest) does far better agree with our Conjectures
about Colours, than either with the Doctrine of the Schools, or with that
of the _Chymists_, both which seem to be very much Disfavour'd by it.

For first, since in the Mixture of the two mention'd Powders I could by the
help of a very excellent _Microscope_ (for ordinary ones will scarce serve
the turn) discover that which seem'd to the naked Eye a Green Body, to be
but a heap of Distinct, though very small Grains of Yellow Orpiment and
Blew Bise confusedly enough Blended together, it appears that the Colour'd
Corpuscles of either kind did each retain its own Nature and Colour; By
which it may be guess'd, what meer Transposition and Juxtaposition of
Minute and Singly unchang'd Particles of Matter can do to produce a new
Colour; For that this Local Motion and new Disposition of the small parts
of the Orpiment did Intervene is much more manifest than it is easie to
Explicate how they should produce this new Green otherwise than by the new
Manner of their being put together, and consequently by their new
Disposition to Modifie the Incident Light by Reflecting it otherwise than
they did before they were Mingl'd together.

Secondly, The Green thus made being (if I may so speak) Mechanically
produc'd, there is no pretence to derive it from I know not what
incomprehensible Substantial Form, from which yet many would have us
believe that Colours must flow; Nor does this Green, though a Real and
Permanent, not a Phantastical and Vanid Colour, seem to be such an Inherent
Quality as they would have it, since not only each part of the Mixture
remains unalter'd in Colour, and consequently of a differing Colour from
the Heap they Compose, but if the Eye be assisted by a _Microscope_ to
discern things better and more distinctly than before it could, i