MINES. 
115 
system is effective, but this is not the case everywhere. When the working 
face is at a long distance from the shaft, the problem of ventilation be- 
comes difficult and requires all the more attention. One instance of the 
lack of such attention was in the mines worked by the East Indian 
Railway at Giridih, and this is probably in part responsible for the 
unsatisfactory physical condition of the miners employed there. In some 
of the smaller mines, also, ventilation is adequate. Unhealthy condi- 
tions affect the health of the worker, not only directly but also 
indirectly, by diminishing his output and consequently his income. 
Sanitation. 
As regards sanitation, attempts have been made to improve 
conditions underground, but as the percentage of infection with hook- 
worm is a reliable guide to the degree of sanitary control, the evidence 
given to us in this connection by the Jharia Mines Board of Health is 
instructive. It appears to be agreed that probably over 90%, of the 
adult labourers in this area are infected, although illness is produced only 
in a very small proportion of cases. An Investigation in the Asansol 
area showed that 839%, of the mines examined were infected with hook- 
worm larvee, that 73%, of the male underground workers were infected 
as compared with 54% of the surface labourers, and that, although 
hookworm infection is widespread in the collieries, hookworm disease is 
apparently altogether absent. It is evident that many of the mines are 
constantly being contaminated and that sanitary conditions underground 
call for improvement. As most of the galleries are spacious, there should 
be little difficulty in providing bucket latrines at convenient spots. 
Although at first it may be difficult to persuade the miners to make use 
of these conveniences, we have little doubt that in time Improvements 
could be effected, and the attempt should be made. A small staff of 
sweepers should be employed to keep the latrines clean and to remove the 
contents of the buckets to the surface daily for final disposal. 
Industrial Disease, | 
We have no evidence to indicate that the miners suffer from the 
industrial diseases and disabilities met with in other countries. Miners’ 
nystagmus is also apparently unknown. This is probably due to the fact 
that it is most unusual to work seams of less than 5 feet in thickness and 
that the miners are ordinarily able to stand upright at their work. 
Sources of Labour. 
The main coalfields lie in or adjacent to areas chiefly inhabited 
by aboriginal tribes. From these tribes the labour force was first drawn 
and they still supply the bulk of the workers. A certain proportion of 
the labour force, consisting mainly of aboriginals, is permanently settled 
within the coalfields, Many of them were attracted by the grant of land 
for cultivation, and they live on the colliery property, devoting a part 
of their time to cultivation. The proportion so settled is higher in the 
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