Auda: Recueil Abrégé des Secrets Merveilleux; ——, 1663.
Zahn, Jean: Oculus Artificialis, etc.; Nuremberg, 1685.
Morley, C.: Collections; London, 1692.
Coronelli, Vincent: Epitome Cosmographique; Venice, 1693.
Pomet: Histoire Générale des Drogues; Paris, 1694 (reprinted, 1736).
Buonanni, Phillipe: Traité des Vernis; Rome, 1713.
Here is a succession of treatises, the earliest written about the time of Gaspar da Salo, and the latest during that of Stradivarius. Here are hundreds of genuine receipts. Is any one of them the right one? Patience and perseverance are necessary, much fitting of old names to their new nomenclatures, and many tiresome comparisons. But these once made, the desired result may be obtained, and the new varnish may possess the old coveted lustrous softness and suppleness. And the colors? the brown, the red, and the yellow?—hidden under quaint and obsolete names, they are all indicated by one and another of these authors, and all are soluble in the one vehicle, forming a colored oil varnish, clear and transparent, which, however long kept, will let fall no sediment.
There is still another branch of this subject which has never, or very rarely, been specified, and this is the ground–toning. In all Italian instruments the wood appears to be permeated with a color varying in intensity from pale yellow to almost orange. This color is quite distinct from that of the varnish; for, however faded by exposure and other causes the latter may be, the ground–tone almost always retains its color. The violins with red varnish afford the finest examples of this ground–toning. On such, its tawny yellow is the most intense, and offers a splendid foil to the superimposed color, toning and giving life to it. How it was composed or applied, whether as a wash or stain, or as a distinct varnish, none of the authors give any information. But from their miscellaneous lists of the drugs, dye–stuffs, and coloring matters common to the Italian markets, it is quite possible that a selection could be made which would fulfill all the required conditions of color and stability.
But though supplied with the ground–tone, another element is needed before the exact reflex of the Italian varnish can be reproduced; and that is the natural color of the old wood.
The problem of the old varnish is solvable by any one who deems the reward worth the trial of patience and perseverance, two elements most effective in the task of interlining the broken sentences of tradition.