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52

Improved Vehicle  ‡                                         

It was the peculiar merit of Van Eyck's invention of [[strikethrough]] Oil [[/strikethrough]] painting in Oil, that his colours dried with a lustre, without sinking in, and therefore not requiring to be oiled for the purpose of repainting & retouching. The secret of this method, though it passed from him to some other Painters, down to the time of Rubens, has been lost to modern Painters. The most learned investigations on this subject have been made by Merimée in Paris, and by Eastlake in London, and the conclusion arrived at is, that their Colours were mixed with an Oleo-resinous Vehicle - that is, Linseed or Nut oil containing Amber, Copal, Sandarac, Mastic, or Resin, in solution. + From the difficulty of obtaining light solutions of Amber or Copal, it appears that Sandarac was substituted, as more solid than Mastic or Resin.

‡ Some English Artists have mixed Copal Varnish with their Colours, and though difficult and troublesome to manage, permanent brilliant effects were produced. It has therefore been considered a great desideratum to form a [[strikethrough]] Megelp [[/strikethrough]] good Vehicle with Copal Varnish- This I have accomplished in the following manner.

A small measure of Poppy Oil is first put on the glass - to this is added as much Carbonate of Magnesia, mixed with the Palette knife, as will thicken it, when well ground with the Muller, to the consistence of a Pigment. From the extreme levity of the Magnesia it will take a considerable bulk, which will be condensed in grinding it by which it is rendered thinner. Then taking a similar measure of undiluted Copal Varnish, mix them intimately with the Muller. [[strikethrough]] My measure is a Salt spoon. [[/strikethrough]] This compound should be freshly prepared from time to time & kept in a small pot, covered from the dust & air, or under Water. 

On setting the Palette, a little of the compound may be mixed with the Colours which are to be used, in the quantity that experience will soon determine, [[strikethrough]] And, for the convenience of additional dilution, a creamy Megelp may be prepared on the Palette, by mixing some of the Compound, with the ordinary Megelp (made of drying oil & Mastic Varnish): or used with Sandarac oil & spirits of Turpentine [[/strikethrough]]

The advantages resulting from the use of this Compound and the modified