The crest of the Ceylon mountains is of stratified crystalline rock, especially gneiss, with extensive veins of quartz, and through this the granite has been everywhere intruded, distorting the riven strata, and tilting them at all angles to the horizon. Hence at the abrupt terminations of some of the chains in the district of Saffragam, plutonic rocks are seen mingled with the dislocated gneiss. Basalt makes its appearance both at Galle and Trincomalie. In one place to the east of Pettigalle-Kanda, the rocks have been broken up in such confusion as to resemble the effect of volcanic action--huge masses overhang each other like suddenly-cooled lava; and Dr. Gygax, a Swiss mineralogist, who was employed by the Government in 1847 to examine and report on the mineral resources of the district, stated, on his return, that having seen the volcanoes of the Azores, he found a "strange similarity at this spot to one of the semi-craters round the trachytic ridge of Seticidadas, in the island of St. Michael."[1] [Footnote 1: Beyond the very slightest symptoms of disturbance, earthquakes are unknown in Ceylon: and although its geology exhibits little evidence of volcanic action (with the exception of the basalt, which occasionally presents an appearance approaching to that of lava), there are some other incidents that seem to suggest the vicinity of fire; more particularly the occurrence of springs of high temperature, one at Badulla, one at Kitool, near Bintenne, another near Yavi Ooto, in the Veddah country, and a fourth at Cannea, near Trincomalie. I have heard of another near the Patipal Aar south of Batticaloa. The water in each is so pure and free from salts that the natives make use of it for all domestic purposes. Dr. Davy adverts to another indication of volcanic agency in the sudden and profound depth of the noble harbour at Trincomalie, which even close by the beach is said to have been hitherto unfathomed. The Spaniards believed Ceylon to be volcanic; and ARGENSOLA, in his _Conquista de las Malucas_, Madrid, 1609, says it produced liquid bitumen and sulphur:--"Fuentes de betùn liquido y bolcanes de perpetuas llamas que arrojan entre las asperezas de la montaña losas de açufre."--Lib. v. p. 184. It is needless to say that this is altogether imaginary.] _Gneiss_.--The great geological feature of the island is, however, the profusion of gneiss, and the various new forms arising from its disintegration. In the mountains, with the exception of occasional beds of dolomite, no more recent formations overlie it; from the period of its first upheaval, the gneiss has undergone no second submersion, and the soil which covers it in these lofty altitudes is formed almost entirely by its decay.