1007 
made from these nodules I could state the presence of some radiolaria 
also in the manganese substance itself. 
The chemical composition is shown in the following analysis of 
one of these nodules made by Prof. H. rrr Mrunun: 
SiO, 24.4 
Fe,O, 25.5 
AO: 9.8 
MnO FOS 
CaO 15 
BaO ().32 
MgO 0.34 
KO Ot 
Na,O 1.46 
NiO 0.28 
CoO 0.16 
CuO 0.12 
Cl (oxyg. aed.) 0.60 
H,O escaping below 110° Tove HEE 
is above 110° 10.2 te 
99.63 
Traces of lead, sulphate and phosphate. 
This substance might be called a Waad rich in iron and silica. 
For the sake of comparison I give this analysis of a nodule of Noil 
Tobee in the following table, after recalculation as if the material 
had been dried at 110°, next to an analysis of manganese nodules 
from the recent deep-sea clay brought up by the Challenger at four 
different stations. 
From this table it appears that the composition varies very much 
in the different nodules *). On account of the high percentage of iron 
they all might be called iron-manganese nodules. The composition 
of the nodule of Noil Tobee lies, except for its contents of alumina, 
within the extreme values, found on analyzing the nodules of 
manganese of the present oceans. 
Type 2. Among the manganese nodules of Noil Tobee there 
are two of a different type, which I have named the second type. 
One of them is broad and flat, measuring 10 >< 9'/, X 3*/, cm.; 
the second is more spherical and smaller. They have a specific 
gravity of 4.2 and their hardness is 6. Thus they are much heavier 
1) An analysis made by A. SCHWAGER of a manganese nodule found in 
red deep-sea clay by the Gazelle in the Pacific Ocean, is given by W. von 
GiMBEL Ref. 5 p. 102. 
