For one of these practical experiments I took a violin which I had made myself and the tone of which, through years of constant use, was therefore quite familiar to me, and gave it a coating of melted resin on the inside. After this was thoroughly dry and hardened, I polished the interior and remarked the before-mentioned smoothness and brilliancy, the obtaining of which firmly convinced me that I had discovered the truth of the matter. Although, after the glueing-on of the belly, all the former conditions of the violin remained unchanged, yet I was astonished to find what a common-place squeaking tone the instrument had acquired, thus proving to me that with the melted resin I had obtained in the end exactly the opposite effect to that which I had hoped for. I was obliged to rest contented with my failure for a long time, when a lucky chance came to my help. It was this. I received a real Caspar da Salo violoncello to repair, which had never been opened and seemed to have been very little played upon, for on it I found an old bridge which I kept as an ornament and curiosity, and which, on closer examination, I found was varnished.
When I opened the cello, it was proved without a doubt that the interior had also received a coating, probably to protect it from dust, etc. The celebrated old violin makers, in so doing, have pursued the right course. This discovery also corroborated my own supposition, that the old masters varnished both the interior and bridge of the instruments they made.
Now, in order to obtain a ground-priming, I paint the violin, when the wood of which it is constructed is in its natural state, three times with pyroligneous acid, with which a golden-brown underground is obtained, then follows a single coating of spirit and balsam of Peru in equal proportions, and after this one or two coats of a weak solution of gamboge or anotta, and finally, over all this I lay on 20 or 30 coats of varnish, according to the thickness required, and which I prepare as follows:—
Dissolve three parts of sandarac and one of mastic in spirit, and in order that it may be laid on more easily, add to each half a litre[1] of varnish, ten drops of oil of turpentine. The colouring of the varnish I obtain from turmeric and bright red sandal-wood by means of spirit, using more or less of it, according as to the lighter or darker tone required; if a brown varnish is required, some soot from turpentine-oil must be added to the spirit.
I have made innumerable experiments with other resins and colouring matters, but in the end I always return to those mentioned above as the best to be used. Dragon’s-blood must not be employed, the colour not being fast.
When the varnish is dry, it must be very carefully polished with finely powdered pumice-stone and linseed-oil, applied with a piece of felt.
[1] Half a litre is very little less than a pint.
XXI. THE CLEANING AND CARE OF THE VIOLIN.
The instrument must always be kept thoroughly clean and after use should be carefully wiped with a silken duster. If any dirt should adhere to it in spite of this precaution, it can be easily removed by gently rubbing it with a piece of linen, moistened with water, and afterwards wiping it over with oil of turpentine. The resin which accumulates on the finger-board and strings can in case of necessity be removed by the application of a little spirit, or better still, by that of Eau de Cologne, but great care must be taken in the application, so that the spirit does not touch the varnish of the belly. Spirit will also clean the strings and remove from them the effect of perspiration; the bridge may also be cleaned with it from time to time, but as stated before, it must be done cautiously, especially in the case of old and valuable instruments of the time of Stradivarius. The more recently constructed violins are mostly varnished with shellac, and consequently are not at all or, at most, very little affected by the application of spirit.
The interior of a violin should also sometimes be cleaned; this can be done by putting through the F-holes two or three handsfull of coarse kitchen salt; these should then be covered with a cloth and the salt well shaken about, as it will thus collect all the dust, resin and other dirt which may be in the violin, and when shaken out will carry all these impurities with it. The strings need not be taken off in order to effect this.