But not to Dispute
about Names or Expressions, the thing it self that is affirm'd as Matter of
Fact, seems to be True enough in most Cases, not in all, or so, as to hold
Universally. For though it be a common observation among Dyers, That
Clothes, which have once been throughly imbu'd with Black, cannot so well
afterwards be Dy'd into Lighter Colours, the praeexistent Dark Colour
infecting the Ingredients, that carry the Lighter Colour to be introduc'd,
and making it degenerate into Some more Sad one; Yet the Experiments lately
mention'd may shew us, that where the change of Colour in Black Bodies is
attempted, not by mingling Bodyes of Lighter Colours with them, but by
Addition of such things as are proper to alter the Texture of those
Corpuscles that contain the Black Colour, 'tis no such difficult matter, as
the lately mention'd Learned Men imagine, to alter the Colour of Black
Bodyes. For we saw that Inks of several Kinds might in a trice be depriv'd
of all their Blackness; and those made with Logwood and Red-Roses might
also be chang'd, the one into a Red, the other into a Reddish Liquor; and
with Oyl of _Vitriol_ I have sometimes turn'd Black pieces of Silk into a
kind of Yellow, and though the Taffaty were thereby made Rotten, yet the
spoyling of that does no way prejudice the Experiment, the change of Black
Silk into Yellow, being never the less True, because the Yellow Silk is the
less good.
Pages:
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181