There are no rocks in Oude, and the only form in which lime is found for building purposes and road-pavements is that of kunkur, which is a carbonate of lime containing silica, and oxide of iron. In proportion as it contains the last, the kunkur is more or less red. 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 animalculae; 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 nodules of the Isle of Sheppey and of Bologne. Doctor O'Shaughnessy further states, that the _reha_ earth, which I sent to him from Oude, is identical with the _sujjee muttee_ of Bengal, and contains carbonate of soda and sulphate of soda as its essential characteristic ingredients, with silicious clay and oxide of iron. But in Oude, the term "_sujjee_" is given to the carbonate and sulphate of soda which remains after the silex has been removed from the reha. The reha is fused into glass after the carbonic acid and moisture have been expelled by heat, and the sujjee is formed into soap, by the addition of lime, fat, and linseed oil, in the following proportions, I am told:--6 sujjee, 4 lime, 21/2 fat, and 11/2 ulsee oil.