522 
MANGANESE DEPOSITS OF IXDIA : ECONOMICS. [PaET III 
in the valuation of manganese -ores are present in the Indian ores. I now 
propose to notice in turn the various constituents found in the Indian 
ores that are not taken into account in the commercial valuation of ores. 
Except where I state otherwise I shall confine myself to the analyses 
made by the Imperial Institute and Messrs. J. and H. S. Pattinson of 
samples collected and specimens selected bv myself. I have 20 complete 
analyses and 62 partial analyses by the Imperial Institute, and 25 com- 
plete and 34 partial analyses by J. and H. S. Pattinson. from which to 
draw conclusions. Though all the partial analyses were of great use in 
the compilation of the preceding tables they mostly do not show any of 
the constituents to be considered here. Hence, except in the case of 
baryta and arsenic I have to rely almost entirely on the complete analy- 
ses. 
The analyses by the Imperial Institute represent the Central Provinces 
only ; those by J. and H. 8. Pattinson represent specimens and samples 
from Vizagapatam, Jhabua, Singhbhum. Panch Mahals, .Satara, Ganjam, 
and a few from the Central Provinces a'so. 
Alumina is invariably present in the Indian manganese-ores, though 
usuallv to a small extent onlv. In 45 complete 
Alumina in manganese- analyses the amount of this^ constituent ranges 
between 0-03% (Lohdongri) and 6-84% 
(Kodur), the average of the whole number being 1"33%. The form 
in which the alumina is present is a matter of speculation. In the case 
of psilomelane and hollandite I have foimd that it can usually be calcu- 
lated into the formula of the mineral as Al4(Mn05)3. It is doubtless 
often present as an impurity mechanically included in the mineral, 
however. There is one variety of ore fo\md in Mysore that seems, as far 
as can be judged from a single analysis by Mr. C. 8. Fawcitt, to be 
particularly aluminous. This is a dull oolitic to pisolitic ore. The 
specimen analysed came from Kumsi and yielded 13"04 per cent. AI2O3. 
Baryta is an almost invariable constituent of manganese-ores. For 
this constituent I can refer not only to the 45 
^^Baryta in n-.anganese- ^^^^^^^^^ analyses, but also to a large number of 
the partial analyses carried out by J. and H. S. 
Pattinson. In 78 analyses the amount of baryta ranges from 0'00% 
in samples and specimens of mixed braunite and psilomelane. with 
braimite usually predominant, from Kodegaon. Kachi Dhfina. Kandri, and 
Kacharwahi, to 1 3*7(1 per cent, in a sample of psilomelane with pyrolusite 
from Bislampur, and 15-08% in a specimen of psilomelane from 
ores. 
