THE FADING OF MERCURY-TONED TRANSPARENCIES.
Inthe multitude of counsellors there is said to be wisdom. This may be true enough in the abstract, but in its special applications it may sometimes lead to bewilderment, more particularly if the counsel of one of the “multitude” be diametrically opposed to that of another counsellor.
In looking over the pages of your useful Year-Book andAlmanacI find that Mr. Brooks has something to say in behalf of a process that has of late received some rude words and rough treatment at the hands of the Editors and others, the process to which I refer being the toning of transparencies by means of mercury. As Mr. Brooks has issued a great number of photo-crayons toned with this agent, it would appear that he felt somewhat uneasy at the prospects of their fading; but he says—“I now feel quite decided that, if the picture be protected by a good varnish, fading will not ensue when a picture is thoroughly toned with mercury.”
Let not Mr. Brooks nor any one else lay this flattering unction to his soul. If varnish be the ægis which is trusted to ward off the destructive effects of fading from the picture, I warn those interested from putting any trust in it; for I have in my possession several of such pictures varnished in the most faultless manner, with varnish of unexceptionable quality, which have faded away into almost invisibility. Now, as these transparencies have been prepared by myself as well as by photographers of recognised high position, including the introducer of the photo-crayon, I believe that I am warranted in assuming that every requisite care has been taken both in the toning and the washing.
I am aware that it has been said that heat is an all-important element in the destruction of a mercury-toned glass picture, and that from this cause the lantern pictures are peculiarly liable to fade, whereas those not subjected to heat will stand. I regret to be compelled to shatter the prop that is raised from this basis to support the stability of the photo-crayon; for in a series of two dozen mercury-toned lantern pictures, purchased not much over two years ago, several which have never been in the lantern or exposed to heat in any way have faded into worthlessness.
I think, therefore, from what I have said, the truth of which the Editors will attest—seeing that I send them herewith several specimens—there is only one lesson to be drawn, and it is this:—Above all things, as you value your reputation, avoid the use of mercury for toning either lantern transparencies or photo-crayon picturesà laSarony.
Don Quixote.