106 
the Demirji chain between Simaul and Koola, particularly about the 
13th or 14th mile from the former, and is overlaid by white lime- 
stone. About the 19th mile, in some places, cliffs of trachytic conglo- 
merate rest upon the peperite, and in others the trachytic conglo- 
merate overlies horizontal beds of white marl belonging to the white 
limestone, and interstratified as before stated, with irregular beds of 
quartz pebbles, 
8. Basalt is exposed south of the Demirji chain at several places, 
but more particularly near and in the Katakekaumene. 
A spur of porphyritic trap occurs about two miles south of Su- 
sugerli. 
Hot Springs burst forth in great force about 75 miles east of 
Singerli. Their temperature is supposed by Mr. Hamilton to be 
equal to that of boiling water. Extensive depositions, in one part 
8 or 10 feet thick, occur around the mouths of the springs; and a 
strong sulphureous smell accompanies the emission of the water; but 
where the temperature had become sufficiently low to permit the 
water to be tasted, no peculiar flavour was perceived. After flowing a 
mile and a half and turning several mills, the water is used for a 
warm bath. ‘The rock from which the springs rise, is a greenish 
brown porphyritic trap. Some copious hot springs issue near the 
lower beds of the tertiary white limestone, a little north of Koola, 
the temperature varying from 123° to 137° Fahr. ‘Two of them are 
situated in the centre of the ruins of an unknown ancient city. Mr. 
Hamilton perceived a slight development of sulphuretted hydrogen 
as. 
The Katakekaumene.—The extent of this interesting tract is much 
less than is assigned to it in published maps, being not more than 7 
miles from north to south, and 18 or 19 from east to west. After 
alluding to his first visit to it in company with Mr. H. E. Strickland, 
and refering to that gentleman’s account of a portion of the district*, 
Mr. Hamilton describes minutely the two systems of volcanos, di- 
stinguished by the state of preservation of the craters and of the 
coulées: he defines also the course of each lava-current, and points 
cut its attendant phenomena—but these details admit of only partial 
abridgement. 
The volcanic products are basalt, lava, and ashes, the first being 
confined to the more ancient craters, and the last to the more modern. 
The numerous older cones are further distinguished by being situated 
on parallel ridges of gneiss and mica slate, and the newer, only three 
in number, by being confined to the intervening alluvial valleys. 
This important distinction Mr. Hamilton explains on the supposition, 
that the elevation of the schistose ridges produced cracks, through 
which, as points of least resistance, the first eruptions of lava found 
vent ; and that these openings becoming subsequently plugged up, 
by the cooling of injected molten matter, the schists were rendered 
so solid, that when the volcanic forces again became active, the lines 
of least resistance were transferred to the valleys. 
* Proceedings, vol. ii., p. 425. 
