65 
MicrRoOGRAPHIA. 
in them. And here I thal] endeavour to fhew by what com pofition all kind 
of compound colours are made, and how there isno colour inthe world — 
but may be made from the various degrees of thefe two colours, together 
with the intermixtures of Black and White. 
And this being fo, as I fhall anon fhew, it feems an evident argun:ent 
to me, that all colours whatfoever, whether in fluid or folid, whether 
in very tranfparent or feemingly opacoxs, have the fame efficient caufe, 
to wit, fome kind of refrattige whereby the Rays that proceed 
from fuch bodies, have their pulfe obliquated or confus d in the manner I 
explicated in the former Sedfion 5 that is, a Red is caus d by a duplicated 
or confus'd pulfe, whofe ftrongeft pulfe precedes,and a weaker follows: 
and a Blue is caus’d by a confus d pulfe,where the weaker pulfe precedes, 
and the ftronger follows. And according as thefe are, more or lels, or 
varioufly mixtand compounded, fo are the fenfations, and confequently 
the phantafims of colours diverfified. | ‘see 
To proceed therefore ; I fuppofe, that all tranfparent colour'd bodies, 
whether fluid or folid, do confift at leaft of two parts, or two kinds of 
fubftances, the one of a fubftance of a fomewhat differing refraZion from 
the other. That one of thefe fubftances which may be call'd the smging 
fubftance, does confift of diftinct parts, or particles of a determinate big- 
nefs which are difféminated, or difpers d all-over the other : That. thele 
particles, if the body be equally,and uniformly colour'd, are evenly 
*dand difpers'd over the other contiguous body ;.That where the 
y is deepeft ting’d, there thefe particles are rang’d thickefts and 
where ‘tis but faintly ting’d, they are rang'd much thinner, but uniformly. 
That by the mixture of another body that unites with either of thefe, 
which has a differing refraction from either of the other,quite differing 
effects will be produc’d,that is,the comfecutions of the confus'd pulfes will 
be much of another kind, and confequently produce: eter faltions and 
phantafms of colours, and from a Red may turn toa Blre, orfroma Blue 
to a Red, &c. ves 
Now, that this may be the better underftood, I fhall endeavour to ex- 
plain my meaning a little more fenfible by a. Scheme + Suppofe we there- 
fore in the feventh Figure of the fixth Scheme, that ABCD reprefentsa 
Vefiel holding a ting’d liquor, let [1 I 1 1,&c. bethe clear liquor,and let 
the tinging body that ismixt with it be: EE, &c. FF, @¢.GG, e+. 
HH, @c. whofe particles (whether round, ‘or fome other. determinate 
Figureis little to our purpofe)are firft of a determinate and equal bulk. — 
Next, they are rang’d into the form of Quincunx, or Equilaterotriangt 
lar order,which that probably they are fo,and whythey are {0,1 thall elfe- 
where endeavour to w. Thirdly,they are of fuch a nature,asdoeseither 
more eafily or more difficultly tranfmit the Rays of lightthen the liquors _ 
if more eafily,a B/neis generated, and if more difficultly, a Red or Scarlet. 
_ And firft, let us fappofe the tinging particlesto be of a fubftancerhat 
does more impede the Rays of light , we fhall find that'the pulfe‘or — 
wave of light movdftom AD to.B C, will ed on,through the con 
taining medinm by the pulfes or waves KK, LL, MM) N ages 230 
S auc 
