( 102 ) 
Colour of each particular Atom, but only the blend- 
ed refleded Rays, proceeding from the adjoining Par- 
ticles: Thus Yellow and Red produce an Orange, 
Yellow and Blue a Green, Sfc. which feems to be 
confirmed by placing two Pieces of Silk near together } 
viz. Yellow and Blue : When by intermixing of their 
reflefted Rays, the Yellow will appear of a light 
Green, and the Blue of a dark Green ; which deferves 
the farther Confideration of the Curious. 
He hath reduced the Harmony of Colouring in 
Tainting to certain infallible Rules , built on this 
Foundation : Whereas, according to the common 
Practice of Painters, their Colouring is the Effed of 
meer Chance or Guefs-work at firft, but improved by 
Experience ; all Painters ufually declaring that there 
can be no certain Rules given for mixing Colours. 
Mr. Le Blon publilhed,. fome Years ago,, an ingenious 
Book on this Subjed, intituled. Color itto ; or, the 
Harmony of Colouring in Painting. 
By thefe Rules he light on the Manner of Print- 
ing any Objed in its natural Colours, by the Means 
of three Plates, and the three primitive Colours ; an 
Art attempted and fought after ever fince the Inven- 
tion of Printing, but in vain, and thought impoffible, 
till he put it in pradice about fifteen Years ago. 
The Plates are engraved chiefly after the Mezzo 
Tinto Manner:, only the. darker Shades , and fome- 
times the Out-Lines where they are to appear very 
(harp, are done with a common Graver. Each Plate 
is not compleatly engraved, but only contrived to take 
fuch a Portion of the Colour as is neceil'ary with the 
other two Plates , to make the Pidure compleat.. 
This 
Z 
