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.