Amber has been admired in all ages and everywhere from its exquisite colour and semi-transparency. Many superstitions were attached to it, and many still believe that to carry a bead made from it is good for the eyesight. It is principally found on the Prussian coast, off the German Ocean, but is also picked up in considerable quantities on the English shore. It is the gum or resin of a now extinct species of pine, which was probably much like that in New Zealand, which produces the gum kauri, which so much resembles amber.
Some amber is yellow and clear like lemon-candy. This is extensively imitated for cigar-holders and pipe-mouthpieces, beads, &c. Then there is the clouded, varying from white to straw-colour, and the beautiful golden-brown, which appears so rich in sunlight; also the dark-brown and black. These dark-brown ambers are generally seen in old ornaments, and are of a kind which is dug out of the earth. Light amber can be darkened to brown by an artificial process.
Gum copal, which comes from Africa, much resembles amber, but is less beautiful and more brittle. Gum kauri, from New Zealand, is very much like it. Both are used to imitate amber.
There are not many who know how to mend amber when broken. I am assured that the following is a trustworthy method:—Warm the pieces, dampen them with caustic potash (ætz-kali), and then press them together. When well done the joining will not be perceptible. It is said that by this process small pieces of amber, amber-dust, &c., can be made into blocks.
In imitating amber, the best pieces of copal are picked out, put into an air-tight vessel, and dissolved in petroleum, sulphuric ether, or benzole. After being dried in blocks this is submitted to a great pressure. As it dries the pressure is increased.
It occurred to me many years ago that the proper way to unite copal to a tough body like amber would be to use a tough or flexible varnish as a binding medium. I find by the work of Lehner on Imitations that he has verified this by experiment. What is also important is, that the process of hardening by pressure is by this means very much facilitated. I should judge, by all chemical laws, that a varnish infused with glycerine in combination with copal, kauri, or amber-dust would, even without pressure, form in time a substance quite as hard as amber, and much less brittle. It is to be desired that some technist would experiment on a variety of gums in this manner, and thus fix or render permanent their beauty. There is a wide field here to be worked. The subject of meerschaum and amber is fully treated in a work entitled Die Meerschaum- und Bernstein-Fabrikationen, von G. M. Raufer; Vienna, A. Hartleben, 2 marks.
I may add that carving amber is a very elegant art, yielding beautiful results. I have known a young lady, the late Miss Catherine L. Bayard, who excelled in it. It is effected chiefly with fine files and emery or glass paper, as, owing to its extremely brittle nature, there is much risk for any save experts to use cutting tools. Amber is a very expensive material, but objects made from it are of more than proportionate value. Those who would practise carving it should begin with pieces of copal. As I have already explained, small fragments and the dust of both amber and copal can be melted and combined with clear turpentine into large masses, which are even tougher than the native gums.
An inferior, but still very pretty, imitation of amber can be made by combining almost any gum properly clarified and coloured; as, for instance, gum-arabic or dextrine with gelatine (best quality white) and glycerine. If thoroughly well combined and dried, this will wear as well as amber. Some of the gums of fruit-trees—e.g., of the peach and cherry—are very beautifully coloured and clear, and seem to be admirably adapted to be hardened by the same process. They occur very frequently in old books of recipes as adhesives or cements. Perfectly clear glue or gelatine with glycerine and transparent dyes form an excellent imitation for beads.
INDIARUBBER AND GUTTA-PERCHA
MENDING INDIARUBBER SHOES AND MAKING GARMENTS WATERPROOF, WITH OTHER APPLICATIONS
Indiarubber or gutta-percha enters into so many familiar and useful objects that there are few people who would not like to know how to repair them when injured.