SEARCH
0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Prev | Current Page 203 | Next

Hooke, Robert, 1635-1703

"Micrographia Some Physiological Descriptions of Minute Bodies Made by Magnifying Glasses with Observations and Inquiries Thereupon"


The same thing may be done by a preparation of _Antimony_, as has been
shewn by the Learned _Physician_, Dr. _C.M._ in his Excellent Observations
and Notes on _Nery's Art of Glass_; and by this means all transparent
colours become _opacous_, or _ammels_. And though by being ground they lose
very much of their colour, growing much whiter by reason of the multitude
of single reflections from their outward surface, as I shew'd afore, yet
the fire that in the nealing or melting re-unites them, and so renews those
_spurious_ reflections, removes also those whitenings of the colour that
proceed from them.
As for the other colours which Painters use, which are transparent, and
us'd to varnish over all other paintings, 'tis well enough known that the
laying on of them thinner or thicker, does very much _dilute_ or deepen
their colour.
Painters Colours therefore consisting most of them of solid particles, so
small that they cannot be either re-united into thicker particles by any
Art yet known, and consequently cannot be deepned; or divided into
particles so small as the flaw'd particles that exhibit that colour, much
less into smaller, and consequently cannot be _diluted_; It is necessary
that they which are to imitate all kinds of colours, should have as many
degrees of each colour as can be procur'd.
And to this purpose, both Limners and Painters have a very great variety
both of Yellows and Blues, besides several other colour'd bodies that
exhibit very compounded colours, such as Greens and Purples; and others
that are compounded of several degrees of Yellow, or several degrees of
Blue, sometimes unmixt, and sometimes compounded with several other
colour'd bodies.


Pages:
191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215