The evidences and often fearful results of recent as well as remote volcanic agency are visible along the whole Jordan valley, and over a large section of the adjoining districts. Beginning at the north we have the crater of Jish, extinct indeed at the surface, but giving palpable proof in tremendous throes of earthquakes that internal fires are still raging. Next follow the copious saline springs of Tabighah, on the northern shore of the Sea of Galilee ; then the sulphureous springs of Tiberias, where the water gushes from the rock at a tempera ture of Fahr. On the eastern side of the Jordan, in the glen of the Yarmuk, are the still hotter and more copious springs of Amatha, issuing from beneath lofty cliffs of igneous rock (Burck hardt, p. 376 ; Handbook for S. and P., pp. 320, It is deserving of special note, that at the time of the great earthquake of 1837, and, as the writer has been informed, on every recurrence of an earthquake in the region, these springs well out in much greater abundance, and their waters increase in warmth. There is thus evidently a subterranean connection between them. The investigations of the writer have tended to establish another point of considerable interest. The towns and villages which have been most severely shaken by earthquakes in this region are those situated on the trap fields ; while villages between them built upon the limestone strata have in many cases escaped almost without injury.
Proceeding still farther south, we find the `copious salt-springs' of Wady man, where the water is 98° Fahr., and emits a fetid odour' (Robinson, iii. 308). Next come the springs of Callirrhoe, near the mouth of Wady Zurka Main, which opens into the north-eastern part of the Dead Sea. They rise in the bottom of a sublime gorge. The base of the cliffs on each side is ruddy ferruginous sandstone, above and through which black and dark gray trap ap pears, while the great body of the mountain behind is limestone. In one place a considerable stream of hot water is seen precipitating itself from a high and perpendicular shelf of rock, which is strongly tinted with the brilliant yellow of sulphur deposited upon it. On reaching the bottom we find ourselves at what may be termed a hot river, so copious and rapid is it, and its heat so little abated ; this con tinues as it passes downwards by its receiving con stant supplies of water of the same temperature . . . . We passed four abundant springs, all within the distance of half a mile, discharging them selves into the stream. . . We had no thermo meter, but the degree of heat in the water seemed very great ; near the source it scalds the hand, which cannot be kept in for the space of half a minute' (Irby and Mangles, p. 468). Lynch found the temperature of the stream to be 95° Fahr. The temperature must be much higher at the source.
Along the shores of the Dead Sea are numerous saline springs and salt marshes. At its southern end is the remarkable ridge of hills called Khashm Usdfim, composed in a great measure of pure salt. Large quantities of bitumen are often found float ing on the Dead Sea, especially, it is said, after earthquakes, as if thrown up by the action of sub terranean fires. And away at the northern extre mity of the valley, at the western base of Hermon, are pits of bitumen (Handbook, p. 453)• All these things indicate volcanic agencies still in action beneath the surface, and tend to illustrate some of the most remarkable events in the long history of Palestine, from the overthrow of Sodom and Gomorrah down to the earthquake of 1837.
Palestine has in all ages been a country of earth quakes The sacred writers show that they were familiar with them. The Scriptures abound in allusions to them, and figures drawn from them. From earthquakes the Psalmist borrows his figures, when he speaks of mountains being carried into the midst of the sea' (xlvi. 2) ; of their skipping like rams, and the little hills like lambs' (cxiv. 4-6). To earthquakes the prophet alludes in his striking language—"f he earth shall reel to and fro like a drunkard, and be removed like a cottage' (Is. xxiv. 2o; cf. Ps. civ. 32 ; r Chron. xvi. 3o ; Jer. x. to ; Hab. iii. 6-8, etc.) There are, however, only two earthquakes expressly named in Scripture. The first was of such serious importance as to form a kind of epoch. Amos dates his vision two years before the earthquake' (i. 1). It took place in the days of Uzziah' (Zech. xiv. 5). The other instance of an earthquake mentioned in Scripture is that of the quaking of the earth and rending of the rocks at the crucifixion (Matt. xxvii. 51). In the seventh year of Herod the Great, Palestine was visited by a tremendous earthquake. (Joseph. Antiq. xv. 5. 2). We read of numerous others since that period (see Kitto, Physical Hirt. of Palestine, ch. iv.) The present bed of the Jordan valley is of a much later formation than either the limestone of the ad joining mountains, or the rock of the trap fields. The crust varies from too to 200 feet in depth, and through this the river has hollowed out for itself a deep tortuous channel, showing along its banks vertical sections. The lower parts consist mainly of tertiary deposits of indurated marl and conglo merate ; while the upper stratum, now composing the surface of the plain, appears to be made up to a large extent of the washings and detritus of the chalk crust which originally covered the neighbour ing highlands, enriched here and there with vege table mould. The coast-plains, Sharon and Phil istia, are coated with a light soil—in some places chalky, in others sandy, with a large admixture of red alluvial clay, and on the top rich vegetable mould. The plains of Esdraelon, Ard el-Hamma, Gennesaret, and Hauran, are coated with deep black clay of extraordinary fertility. It is composed in a great degree of disintegrated lava, and perhaps, to some extent, volcanic ashes, together with a large quantity of decomposed vegetable matter— the residue of the forests that appear to have at one period extended over all Palestine.
Besides the incidental notices in the travels of Burckhardt, and Drs. Wilson, Robinson, and Thom son, the following works contain the fullest informa tion we possess on the geology of the different parts of Palestine :-1. Anderson's Geological Reconnais sance, in Lynch's Official Report. His researches were confined to the Jordan valley and the regions immediately adjoining. 2. Russegger's Reisen, vol. iii. This work embraces an account of the environs of Jerusalem, Hebron, and Joppa, and parts of Galilee around Nazareth and Tiberias. 3. Poole's short paper in the yournal of R. G. S., vol. xxvi., giving brief notes of his journey from Joppa to Jerusalem and the Dead Sea, and then along the western shore, and round the southern end to the promontory of Lisan. 4. Wetzstein's Reisebericht fiber Hauran and die Trachonen, giving some ac count of the remarkable trap-fields of the Lejah, Jebel Hauran, the Safah, etc. 5. Porter's Five Years in Damascus, containing a full description of the physical geography of Bashan.