The effect of the colours is the same in both systems, each will have and preserve its peculiar character, as to the manner of painting; if you paint your subject in the light and airy stile of the Carlo Marat school, when the colours will be fixed you will have the high colouring of Rubens.
On WAX.
It is not material for me to decide which of the two ought to be preferably employed, bees-wax simple, or virgin-wax.—For large works that will be exposed to the air, I should prefer the former; artists will see by a few trials which will suit their taste best.
On VARNISH.
Varnishes are not required, as has already been observed; but as our eyes have been used so much to see colours, not in their natural hue, but disguised by varnish, those that should like to please themselves in this point may use the following method.
First lay on with a clean spunge a substantial lay of the white of eggs, and work it well upon the picture. This dry, lay on any varnish commonly used for oil painting, and your picture will look as if painted with oil-colours.
This varnish may be taken off at pleasure, the uppermost by rubbing the surface of the picture with a rag dipped in spirit of wine or turpentine, the white of eggs by washing the picture with water. It is not adviseable to lay a varnish of spirits or gums, without first using the white of eggs, as spirit of turpentine is the menstruum of wax.
EXPERIMENTS.
To adopt and practise in earnest any new system without sufficient trials and proofs of its merit, may be called going wilfully astray.—To avoid deceiving myself in the new system before us, I, after having been convinced of its advantageous practicability, set about to ascertain the other great point, the stability of the colours; for this end, and to know more exactly how much every colour would vary from its original hue in a certain space of time, as well in regard to the same system as in opposition to oil-colours, I proceeded as follows.