562 
aud ore in a groundmass of the same constituents with small quan- 
tities of glass. 
Il. Products of the eruption of 1904. 
Hypersthene augite andesites from the dome, which had gradually 
arisen in the crater after the eruption of 1904 and was exploded 
for the greater part at the eruption of 1914. Hypersthene augite 
andesites from the lava-flow, which has flowed down the southern 
slope into the sea. 
Xenoliths in these rocks. 
They are fine-, to coarsegrained, sometimes porphyritie rocks, 
generally rich in plagioclase and moreover containing one or more 
of the following minerals: hypersthene, augite, amphibole of varying 
colour and magnetite. Glass sometimes occurs and is enelosed within 
felspars, or occurs between the other constituents. The plagioclase of 
the xenoliths is, in contradistinction to that of the enclosing ande- 
sites, of a much less strongly zonary, or of homogeneous structure 
and belongs to basic mixtures with the composition of basic labra- 
dorite or bytownile. 
The following mineral-combinations may be distinguished: 
1. plagioclase, brown amphibole, little hypersthene, augite and 
magnetite. The brown amphibole has been resorbed more or less in 
various xenoliths and has sometimes disappeared completely. 
2. plagioclase, brown, faintly resorbed, amphibole with much 
hypersthene, augite and magnetite. 
3. plagioclase, completely resorbed brown and not resorbed light- 
green amphibole with little hypersthene, augite and magnetite. 
4. plagioclase, light-green amphibole, hypersthene, augite and 
magnetite. 
5. plagioclase, hypersthene, augite, magnetite and light-brown glass. 
6. plagioclase with little magnetite. 
7. fine-granular mixture of lath-shaped plagioclase, glass, magne- 
tite, and little pyroxene. 
ILI. Products of the eruption of 1914. 
A very considerable portion of the material that now covers the 
slopes of Ruang, dates no doubt from the latest eruption of the 
volcano. It is beyond doubt that among the products of the latest eruption 
are the blocks and bombs overlying the lava-flow of 1904, which are 
distinguished from all the other material emitted by their light-grey, 
fresh colour. These rocks are also pyroxene-andesites with both hy per- 
sthene and augite. 
