The diseases in the latter are, I believe, more commonly fatal than they are in the former; and are considered by the people to arise solely from the poisonous quality of the water, which is often found in wells to be covered with a thin crust of petrolium.

Diseases of the same character prevail at the same two seasons in the jungles, above the sources of the Nerbudda and Sohun rivers, and are ascribed by the people to the same causes--those which take place after the rains, to bad air; and those which take place immediately before the rains, after the cold and dry seasons, to bad water.

The same petrolium, or liquid bitumen, is found floating on the spring waters in the hot season, when the most fatal diseases break out in the jungles, about the sources of the Nerbudda and Sohun, as in the Oude Tarae; and, in both places, the natives appear to me to be right in attributing them to the water; but whether the poisonous quality of the water be imparted to it by bitumen from below, or by the putrid leaves of the forest trees from above, is uncertain; the people drink from the bituminous spring waters at this season, as well as from stagnant pools in the beds of small rivers, which have ceased to flow during part of the Cold, and the whole of the hot, season.

These pools become filled with the leaves of the forest trees which hang over them.
The bitumen, in all the jungles to which I refer, arises, I believe, from the _coal measures_, pressed down by the overlying masses of sandstone strata, common to both the Himmalaya chain of mountains over the Tarae forest, and the Vendeya and Sathpoor ranges of hills at the sources of the Nerbudda and Sohun rivers.

It is, however, possible that the water of these stagnant pools, tainted by the putrid leaves, may impart its poison through the medium of the air in exhalations; and I have known European officers, who were never conscious of having drunk either of the waters above described, take the fever (owl) in the month of May in the Tarae, and in a few hours become raving mad.