Amber is the resinous exudation of trees like the "Copal gum" of East Africa and the "Kauri resin" or "Dammar" of New Zealand. Both of these products are very much like amber in appearance, and can be readily mistaken for it. The trees which produced the amber of the Baltic were conifers or pine trees, and flourished in early Tertiary times (many millions of years ago). Their leaves, as well as insects of many kinds, which have been studied and named by entomologists, are found preserved in it. There is a very fine collection of these insects in the Natural History Museum in London. It is probable that more than one kind of tree produced the amber-gum, and that its long "fossilization" has resulted in some changes in its density and its chemical composition. The East African copal is formed by a tree which belongs to the same family as our beans, peas, and laburnum. It is obtained when freshly exuded, but the best kind is dug by the negroes out of the ground, where copal trees formerly grew and have left their remains, so that copal, like amber, is to a large extent fossilized. The same is true of the New Zealand dammar or kauri gum, which is the product of a conifer called "Agathis australis," and is very hard and amber-like in appearance. Chemically amber, copal, and dammar are similar to one another but not identical. Amber, like the other two, has been used for making "varnish," and the early Flemish painters in oils, as well as the makers of Cremona violins, made use of amber varnish.
A medicament called "eau de luce" was formerly used, made by dissolving one of the products of the dry distillation of amber (called "oil of amber") in alcohol. Now, however, amber is used only for two purposes—besides decoration—namely, for the mouthpieces of pipes and cigar tubes and for burning (for amber, like other resins, burns with a black smoke and agreeable odour) as a kind of incense (especially at the tomb of Mahomet at Mecca). These uses are chiefly Oriental, and most European amber now goes to the East. In China they use a fine sort of amber, obtained from the north of Burma. The use of amber as a mouthpiece is connected with its supposed virtues in protecting the mouth against poison and infection. It is softer than the teeth, and therefore pleasant to grip with their aid; but as a cigar or cigarette tube it is disadvantageous, as it does not absorb the oil which is formed by the cooling of the tobacco smoke passing along it, but allows it to condense as an offensive juice.
Forty years ago an old lady used to sit in the doorway of her timber-built cottage in the village of Trimley (where there are the churches of two parishes in one churchyard), smoking a short clay pipe and carving bits of amber found on the Suffolk beach into the shape of hearts, crosses, and beads. She would carve and polish the amber you had found yourself whilst you joined her in a friendly pipe. You were sure in those days of the genuine character of the amber, jet, and agate sold as "found on the beach." Nowadays these things, as well as polished agates and "pebbles from the beach," are, I am sorry to say, manufactured in Germany, and sent to many British seaside resorts, like the false coral and celluloid tortoise-shell which, side by side with the genuine articles, are offered by picturesque Levantines to the visitors at hotels on the Riviera, and even in Naples itself. Nevertheless, genuine and really fine specimens of amber picked up on the beach and polished so as to show to full advantage their beautiful colour and "clouding" can still be purchased in the jeweller's shop at Aldeburgh on the Suffolk coast near the great pebble beach of Orfordness.
There are difficulties about using the word "amber" with scientific precision. The fossil resins which pass under this name in commerce, and are obtained in various localities, including the Prussian mines on the Baltic, are undoubtedly the product of several different kinds of trees, and, from the strictly scientific chemical point of view, they are mixtures in varying proportions of different chemical substances. The merchant is content with a certain hardness (which he tests with a penknife), transparency, and colour, and also attaches great importance to the test of burning a few fragments in a spoon, when, if the material is to pass as "amber," it should give an agreeable perfume. Scientifically speaking, "amber" differs from other "resins," including copal, in having a higher melting point, greater hardness, slighter solubility in alcohol and in ether, and in containing "succinic acid" as an important constituent, which the other resins, even those most like it, do not. True amber thus defined is called "succinite," but several other resins accompany it even as found in its classical locality—the Baltic shore of Prussia—and, owing to their viscid condition before fossilization, may have become mixed with it. One of these is called "gedanite," and is used for ornamental purposes. It is more brittle than amber, and contains no succinic acid. It is usually clear and transparent, and of a pale wine-yellow colour.
It is not possible to be certain about the exact nature of what appears to be a "piece of amber" thrown up on the seashore, without chemical examination. A year or two ago a friend brought to me a dark brownish-yellow-coloured piece of what looked like amber, which (so my friend stated) had been picked up on the shore at Aldeburgh. It was as big as three fingers of one's hand, very transparent and fibrous-looking, owing to the presence of fine bubbles in its substance arranged in lines. I found an exactly similar piece from the same locality in the collection of the Natural History Museum. It was labelled "copal," and, I suppose, had been chemically ascertained to be that resin and not "amber," or, to use the correct name, "succinite." How either of these pieces got into the North Sea it is difficult to say. Though the "copal" of commerce is obtained from the West Coast of Africa, it may occur (though I have not heard that it does) associated with true amber in Prussia. A fossilized resin very similar to copal is found in the London clay at Highgate and elsewhere near London, and is called "copalite." It is possible, though not probable, that the bits of amber found on our East Coast beaches are derived from Tertiary beds, now broken up and submerged in the North Sea, and do not travel to us all the way from the Baltic.
CHAPTER X
SEA-WORMS AND SEA-ANEMONES
LET us now leave the beach-pebbles and go down on to the rocks at low tide in order to see some of the living curiosities of the seashore. There are some seaside resorts where, when the tide goes down, nothing is exposed but a vast acreage of smooth sand, and here the naturalist must content himself with such spoils as may be procured by the aid of a shrimping-net and a spade. Wading in the shallow water and using his net, he will catch, not only the true "brown shrimp," but other shrimp-like creatures, known as "crustacea"—a group which includes also the lobsters, hermit-crabs, true crabs, and sand-hoppers, as well as an immense variety of almost microscopic water-fleas.
He will also probably catch some of the stiff, queer little "pipe-fish," which are closely related to the little creatures known as "sea-horses." Pipe-fish are very sluggish in movement, almost immobile, whilst the "sea-horse" or hippocampus—only to be taken by the dredge amongst corallines in deep water on rocky bottoms (as, for instance, in the Channel Islands)—goes so far as to curl his tail, like a South American monkey, round a stem of weed and sit thus upright amidst the vegetation. Even when disturbed he merely swims very slowly and with much dignity in the same upright position, gently propelled by the undulating vibratory movement of his small dorsal fin. The male in both pipe-fish and sea-horses is provided with a sac-like structure on the ventral surface in which he carries the eggs laid by the female until they are hatched.