BOOK II.

35

directions of the wind, throws both these substances on shore, and for thisreason the search for amber demands as much care as does that for coral.

Moreover, it is necessary that those who wash the sand or evaporatethe water from the springs, should be careful to learn the nature of thelocality, its roads, its salubrity, its overlord, and the neighbours, lest onaccount of difficulties in the conduct of their business they become eitherimpoverished by exhaustive expenditure, or their goods and lives areimperilled. But enough about this.

The miner, after he has selected out of many places one particular spotadapted by Nature for mining, bestows much labour and attention on theveins. These have either been stripped bare of their covering by chanceand thus lie exposed to our view, or lying deeply hidden and concealed theyare found after close search; the latter is more usual, the former morerarely happens, and both of these occurrences must be explained. Thereis more than one force which can lay bare the veins unaided by the industryor toil of man; since either a torrent might strip off the surface, which hap-pened in the case of the silver mines of Freiberg (concerning which I have

“ cells, nowhere continuous to the matter of them. It is said that in Melos the pumice“ is produced in this manner in some other stone, as this is on the contrary in it; but the“ stone which the pumice is found in is not at all like the Lipara stone which is found in it." Certain stones there are about Tetras, in Sicily, which is over against Lipara, which“ empty themselves in the same manner in the fire. And in the promontory called Erineas,“ there is a great quantity of stone like that found about Bena, which, when“ burnt, emits a bituminous smell, and leaves a matter resembling calcined earth. Those" fossil substances that are called coals, and are broken for use, are earthy; they kindle," however, and burn like wood coals. These are found in Liguria, where there also is amber,“ and in Elis, on the way to Olympia over the mountains. These are used by smiths.”(Based on Hill’s Trans.). Dioscorides and Pliny add nothing of value to this description.

Agricola ( De Nat. Fos., p. 229-230) not only gives various localities of jet, but alsorecords its relation to coal. As to the latter, he describes several occurrences, and describesthe deposits as vena dilatata. Coal had come into considerable use all over Europe, particu-larly in England, long before Agricola’s time; the oft-mentioned charter to mine sea-coalgiven to the Monks of Newbottle Abbey, near Preston, was dated 1210.

Amber was known to the Greeks by the name electrum, but whether the alloy of thesame name took its name from the colour of amber or vice versa is uncertain. The gum issupposed to be referred to by Homer (Od. xv. 460), and Thales of Miletus (640-546 b.c.)is supposed to have first described its power of attraction. It is mentioned by many otherGreek authors, Aischylus, Euripides, Aristotle, and others. The latter ( De Mirabilibus,81) records of the amber islands in the Adriatic, that the inhabitants tell the story thaton these islands amber falls from poplar trees. “ This, they say, resembles gum and hardens“ like stone, the story of the poets being that after Phaeton was struck by lightning his sisters“ turned to poplar trees and shed tears of amber.” Theophrastus (53) says : “ Amber is“ also a stone ; it is dug out of the earth in Liguria and has, like the before-mentioned (lode-“ stone), a power of attraction.” Pliny (xxxvn., 11) gives a long account of both thesubstance, literature, and mythology on the subject. His view of its origin was :Certainly amber is obtained from the islands of the Northern Ocean, and is called by the‘ Germans glaesum. For this reason the Romans, when Germanicus Caesar commanded inthose parts, called one of them Glaesaria, which was known to the barbarians as‘ Austeravia. Amber originates from gum discharged by a kind of pine tree, like gum from‘ cherry and resin from the ordinary pine. It is liquid at first, and issues abundantly and„ hardens in time by cold, or by the sea when the rising tides carry off the fragments from„ the shores of those islands. Certainly it is thrown on the coasts, and is so light that it„ a PPears to roll in the water. Our forefathers believed that it was the juice of a tree, for„ they called it succinum. And that it belongs to a kind of pine tree is proved by the odour„ . the pine tree which it gives when rubbed, and that it burns when ignited like a pitchpine torch.” The term amber is of Arabic origin—from Ambar —and this term wasadopted by the Greeks after the Christian era. Agricola uses the Latin termsuccinum and (De Nat. Fos., p. 231-5) disputes the origin from tree gum, and contends for

submarine bitumen springs.