Journey through Souths North and East Iceland. 165 
' pitchstone-porphyry afforded me an explanation of the appear- 
ances in the obsidian hill near Krabla, where a similar bed ap- 
pears to have been completely melted. Masses of porphyry-slate 
were still very discernible in the Krabla obsidian ; and the sphae- 
rulite in the pitchstone, which the fire had converted into ob- 
sidian, appeared to be the same mineral as that found in Mexi- 
co, and described under the name EquinoUte, and for which I 
would propose, as a more appropriate name, that of Volcanic 
SjphcErulite. 
In the island of Heyma Ey, there is only one place where 
fresh-water occurs, and it is in a track where volcanic rocks are 
wanting. On the Eyaflalla-Yokull there are portions of trap-por- 
phyry still unmelted, and these afford fresh-water ; but those parts 
which are in the state of lava afford none. The rivers Markerfliot, 
Thiorsaa, and Olvessaa, which flow through lava, arise from the 
glaciers. All those parts of the Guldbringe Syssel which are cover- 
ed with lava, afford no fresh- water. . At Cape Reikaness, there is 
a district of volcanic water situated in lava. In this district, also, 
there is a boiling marsh, of about 300 paces in circumference, 
which appears as if surrounded with fresh-burnt lava. The 
smoking parts which I dug up, were composed of a muddy hot 
mass, more or less mixed with sulphur, and of various colours, 
as blue, red, &c. I extracted several hard portions from the 
hot muddy mixture : these I broke when cold, and found, that 
in the centre they had the characters of basaltic lava, but to- 
wards the surface gradually passed into indurated red or grey 
mud. On an eminence in the neighbourhood, I observed whole 
deposites of siliceous sinter. 
In the same manner as the hot-springs of Reikaness produce 
lava, we saw those of Krysuvick form basalt, and those of the 
Geyser trap-porphyry. 
At Krysuvick in the south, and at Namafell in the north of 
Iceland, are great chemical laboratories. In both places, we al- 
most see Nature in the act of forming sulphur, alum, silica, 
hme, oxide of iron, iron-pyrites, gypsum, basalt, lava, and per- 
phyry. 
In Iceland, we find volcanic and neptunian formations con- 
joined ; the connecting link between the two, being the Volcanic- 
