Chap. XLI. ] 
SHIMOGA DISTRICT. 
1131 
A common variety of ore is one showing pisolitic or oolitic struc- 
tures. In this variety of ore the spherulitic grains range from 
to I or even ] inch in diameter ; perhaps g inch is the most usual 
size. These spherules frequently show a concentric structure, and are 
composed of psilomelane. The matrix in which they are set is often 
softer and then gives a brownish black streak and is to be called wad. 
At other times the matrix itself is composed of psilomelane,. which in 
both pisolites and matrix is of the lead-Uke variety. It seems as if 
the ore first formed is wad in which the pisolites grow, and as if 
at a later stage the wad matrix itself changes into psilomelane. Another 
minernl that is fairly common in these deposits is a hard bright 
crystalline one that occurs in irregular patches, streaks, spots, and 
veinings, scattered throughout the psilomelane of the ores at the 
various deposits. This mineral has not yet been closely examined ; 
from its association with psilomelane and general appearance it 
suggests hollandite, or possibly braunite. The one specimen I tested 
gave a siliceous residue on solution in acid, but it did not seem to be 
gelatinous. On the other hand the solution did not react for barium, 
as it probably would if it were hollandite. Hence until a complete 
quantitative analysis be made it will not be possible to assign it 
a name. The bright crystalline mineral seen in different specimens, 
however, may not always be the same. It seems almost certain that 
a certain proportion of it must be hollandite, and not improbable that 
some of it is braunite ; it is further possible that a portion of it may re- 
present polianite (see page 11 19) or even a new species. The only mineral 
I have seen in the Shimoga deposits showing definite crystalline 
forms is pyrolusite, which is often found lining cavities, in the form of 
beautifully developed crystals of small size, showing various prisms, 
capped as a rule by the basal plane. 
With regard to the quality of the ores I am not able to give figures 
based on the analyses of samples taken by myself. 
Quality of the ores. , 
But Mr. C. S. Fawcitt, chemist to the Mysore 
Manganese Company, Limited, has kindly furnished me with the figures 
shown in the first and second columns below ; and Miss A. E. Dawson, 
of the Shimoga Manganese Company, with analyses from which the 
figures shown in the third column are taken. Mr. Fawcitt 'a figures 
