quite tepid, notwithstanding the extreme cold of the air.
On procuring a thermometer, it was found to have a
temperature of 69°. Advancing up the stream, we found
that numerous hot springs rose on its hanks, and sometimes
under the water. The hottest of these had a temperature
of 174°. From these springs gas was copiously
evolved, smelling strongly of sulphur; and in their immediate
neighbourhood the water of the little river had a
faintly sulphurous taste, though elsewhere it was quite
pure and good. The stream, which was perhaps twenty
feet wide, was usually rather deep. Dense masses of
aquatic weeds, chiefly species of Zannichellia and Potamogetón,
grew in the water, and along the margins their
dead stems, mixed with mud, formed immense banks,
scarcely strong enough to bear the weight of a man, and
yet seemingly quite solid. A small crustaceous animal
was common among the weeds, but though I searched
with care I could find no shells. The stream was full
of fish, which swarmed among the weeds, and darted
backwards and forwards in the tepid water in immense
shoals. They were generally about six inches in length,
and appeared to my inexperienced eye to belong to two
or three species, all different from those which had been
seen at Hanle. In the hottest water of the hot springs
I collected three species of Conferva.
The existence of the tree Myricaria in the gorges between
Pugha and the Indus, which had appeared to us at
the time very remarkable, was fully explained by the occurrence
of the hot springs, and the consequent high
temperature of the water of the stream, and was peculiarly
interesting as an illustration of the influence of
temperature upon vegetation. It may fairly be considered,
I think, as a proof, that arboreous vegetation
does not cease at great elevations in consequence of the
rarefaction of the air, but only on account of the diminution
of temperature which usually accompanies increased
elevation. The trees of Myricaria, it must be
observed, came abruptly to an end with the ravine, none
occurring on the open plain. We cannot suppose that
the trifling increased elevation caused their disappearance;
it seems probable that the narrow walls of the gorge, by
concentrating the heat, prevented its escape, and that,
therefore, the temperature was more elevated than in
the open plain, where the action of winds and free radiation
combined to lower it. The occurrence of fish in
the water of Pugha, at an elevation of nearly 15,500
feet above the level of the sea, is also very remarkable,
and still more strikingly demonstrative of the same fact,
inasmuch as it would certainly not have been very surprising
that air at that elevation should, from its rarity,
be insufficient for the support of life in animals breathing
by gills.
At the gorge, where the narrow ravine expands into
the lake plain of Pugha, the rock is clay-slate, but the
hills which skirt the open plain are micaceous schist,
varying much in appearance, often with large crystals of
garnet, and crumbling rapidly to decay. On the surface
of the plain lay many scattered boulders of a peculiar
kind of granite, evidently transported from a considerable
distance along the stream; and in all the central parts of
the plain, a very remarkable conglomerate in horizontal
strata, consisting of angular fragments of the surrounding