388 
1st Eruption, 
a . d . 894 
Interval 
since previous Eruption. 
2d 
934 
40 
years, 
3d 
1245 
... 311 
11 
4th 
1262 
17 
11 
5th 
1311 
49 
1 1 
6th 
1416 
105 
11 
7th 
1580 
164 
11 
8th 
1612 
32 
ii 
9th 
1625 
13 
ii 
10th 
1660 
35 
ii 
11th 
1721 
61 
ii 
12th 
1727 
6 
n 
13th 
1755 
28 
11 
14th 
1823 
68 
11 
15th 
1860 
37 
V 
d. Details of the Eruption of May 1860. 
e. Main peculiarity of the eruptions of Kotlugja — water 
and ice-floods. 
f. Physical and geological character of the surrounding 
country, as determined by the phenomena and products 
of the eruptions of Kotlugja. 
(2.) Notes on Icelandic Geology and Mineralogy . 
a. Palagonite and the palagonitic rocks ; especially those of 
Seljadalr, Fossvogr, and the coast between Reykjavik 
and Havnafiord. 
b. Basalts. 
c. Obsidians. 
d. Pumice-tuffs, 
(3.) Chemical Analyses: of— 
a. The waters of the Laugarnes hot-spring near Reykjavik, 
b. Muds and other deposits from the same spring. 
c. Muds and other deposits from the hot-springs of Krisuvik, 
d. Sulphur-muds from Krisuvik. 
e. Havnafiordite [of Forchhammer] from Havnafiord near 
Reykjavik. 
/. Palagonite- tuffs from the coast between Reykjavik and 
Havnafiord. 
g . Basalts and Trachytes from the Island of Videy near 
Reykjavik. 
The large amount of Silica found in the water of the Laugarnes 
hot-springs is confirmatory of all former published analyses of the 
