That which contains none is of a dirty-white. It is found in many
parts of India in thin layers, or amorphous masses, formed by
compression, upon a stiff clay substratum; but in Oude I have seen it
only in nodules, usually formed on nuclei of flint or other hard
substances. The kingdom of Oude must have once been the bed, or part
of the bed, of a large lake, formed by the diluvial detritus of the
hills of the Himmalaya chain, and, as limestone abounds in that
chain, the bed contains abundance of lime, which is taken up by the
water that percolates through it from the rivers and from the rains
and floods above. The lime thus taken up and held in solution with
carbonic add gas, is deposited around the small fragments of flint or
other hard substances which the waters find in their way. Where the
floods which cover the surface during the rains come in rivers,
flowing from the Himmalaya or other hills abounding in limestone
rocks, they of course contain lime and carbonic-acid gas, which add
to the kunkur nodules formed in the bed below; but in Oude the rivers
seldom overflow to any extent, and the kunkur is, I believe, formed
chiefly from the lime already existing in the bed.

Doctor O'Shaughnessy, the most eminent chemist now in India, tells me
that there are two marked varieties of kunkur in India--the red and
the white; that the red differs from the white solely in containing a
larger proportion of peroxide of iron; that the white consists of
carbonate of lime, silica, alumina, and sometimes magnesia and
protoxide of iron. He states that he considers the kunkur to be
deposited by calcareous waters, abounding in infusorial animalculæ;
that the waters of the annual inundation are rich in lime, and that
all the facts that have come under his observation appear to him to
indicate that this is the source of the kunkur deposit, which is seen
in a different form in the Italian travertine, and the crescent