Di/Jertathn on Paini'mg in OIL t%J ■ 



lofing Its tranfparency. One thing I have frequently had 

 occafion to remark in the ufe of water colours (in a tranfpa- 

 renl ftate), that the more gum is mixed with them, the 

 fooner they fly. As far as glazing goes to enrich a colour 

 it is neceflary; but that is a very ditFerent praftice from the 

 one I now fpeak of. 



Many fubftances employed as pigments give black, or 

 dead, heavy colours ; as Pruffian blue, indigo, dark lake, 

 and indeed all colours that are tranfparent when viewed in a 

 lump ; but, fpread on a white ground, or mixed with scny 

 colourlefs matter, they appear in ail their vigour. If, inftead 

 of a white ground, a grey or brown is ufed, the vivacity will 

 be more or lefs in proportion to its darkncfs. Thefe fa<3:3 

 furnifli ftrong reafons for preferring a white ground, and 

 may account for the darknefs in many of the Venetian pic- 

 tures, from their glazing with tranfparent colours on a dark 

 fiirface, and, as before ftated, the lofs of clearnefs in the ve- 

 Iiicle ufed (no doubt a gum) j but this appears to have been 

 only an occafional pra6lice. 



The Dutch painters, whofe mechanical excellence was 

 inferior to none, always ufed wliite grounds prepared with 

 the greatcft care. They fpread well-waflied chalk mixed 

 with fize over the furface to be painted on, v/hich if nicety 

 was required the}' pumiced, and repeated the operation 

 till the furface was even ; after which they laid over it 3 

 coat of the finefl; flake white. The whole pi<Slure was then 

 painted fair, (that is, with a body of colour,) except the (hades, 

 which were kept clear and tranfparent, and received an addi- 

 tional luftre from the ground. That this was their practice 

 may be eafily fecu in all their interior fccnes and the ciofe 

 parts of their pifturcs. 



It is much to be win)cd that, inflead of brilliancy, per^ 

 mancnc)' were fought after; while t'ac Venetian pi(Slurc3 are 

 going faft to decay, the works of Van Eyck, Quintin Mat- 

 fys, and John de Mabufe, remain frefli and vigorous. 



Willi rcfposSt to (hadow being a privation of light, it is 

 7 readily 



