Dr. Clarke remarks, that in the neighborhood of Cana there are several basaltic appearances. The extremities of columns, prismatically formed, penetrated the surface of the soil, so as to render the path very rough and unpleasant. These marks of regular or of irregular crystallization generally denote, according to his opinion, the vicinity of water lying beneath their level. The traveller, having passed over a series of successive plains, resembling in their gradation the order of a staircase, observes, as he descends to the inferior stratum upon which the water rests, that where rocks are disclosed the symptoms of crystallization have taken place, and then the prismatic configuration is commonly denoted basaltic. Such an appearance, therefore, in the approach to the Lake of Tiberias is only a parallel to similar phenomena exhibited by rocks near the Lakes of Locarno and Bolsenna in Italy, by those of the Wenner Lake in Sweden, by the bed of the Rhine near Cologne in Germany, by the Valley of Ronca in the territory of Verona, by the Pont de Bridon in the state of Venice, and by numerous other examples in the same country. A corresponding effect is produced on a small scale on the southern declivity, of Arthur Seat, near Edinburgh, where the hill overhangs the Lake of Duddingstone; and numerous other instances are known to occur in the islands which lie between the coast of Ireland and Norway, as well as Spain, Portugal, Arabia, and India. When these crystals have obtained a certain regularity of structure, the form is often hexagonal, or six-sided, resembling particular kinds of spar, and the emerald. Patrin, during his travels in the deserts of Oriental Tartary, discovered when breaking the Asiatic emerald, if fresh taken from the matrix, not only the same alternate concave and convex fractures which sometimes characterize the horizontal fissures of basaltic pillars, but also the concentric layers which denote concretionary formation: It is hardly possible to have a more striking proof of coincidence, resulting from similarity of structure, in two substances otherwise remarkably distinguished from each other. In this state science remains at present, concerning an appearance in nature which exhibits nothing more than the common process of crystallization upon a larger scale than has usually excited attention. Suffice it to remark, that such a phenomenon is very frequent in the vicinity of very ancient lakes, in the bed of all considerable rivers, or by the borders of the ocean.[187]