And that this is not _gratis dictum_, I shall add one instance of this
kind, wherein the thing is most manifest.
If you take Blue _Smalt_, you shall find, that to afford the deepest Blue,
which _caeteris paribus_ has the greatest particles or sands; and if you
further divide, or grind those particles on a Grindstone, or _porphyry_
stone, you may by _comminuting_ the sands of it, _dilute_ the Blue into as
pale a one as you please, which you cannot do by laying the colour thin;
for wheresoever any single particle is, it exhibits as deep a Blue as the
whole mass. Now, there are other Blues, which though never so much ground,
will not be _diluted_ by grinding, because consisting of very small
particles, very deeply ting'd, they cannot by grinding be actually
separated into smaller particles then the operation of the fire, or some
other dissolving _menstruum_, reduc'd them to already.
Thus all kind of _Metalline_ colours, whether _precipitated_, _sublim'd_,
_calcin'd_, or otherwise prepar'd, are hardly chang'd by grinding, as
_ultra marine_ is not more _diluted_; nor is _Vermilion_ or _Red-lead_ made
of a more faint colour by grinding; for the smallest particles of these
which I have view'd with my greatest Magnifying-Glass, if they be well
enlightned, appear very deeply ting'd with their peculiar colours; nor,
though I have magnified and enlightned the particles exceedingly, could I
in many of them, perceive them to be transparent, or to be whole particles,
but the smallest specks that I could find among well ground _Vermilion_ and
_Red-lead_, seem'd to be a Red mass, compounded of a multitude of less and
less motes, which sticking together, compos'd a bulk, not one thousand
thousandth part of the smallest visible sand or mote.
Pages:
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203