animal or vegetable matter, these carbonates or sulphates of soda, as they rise to the surface, might be formed into nutriment for plants, and taken up by their roots; or in one well flooded occasionally with fresh water, any superabundance of the salts or their bases might be taken up in solution and carried off.  The people say, that the soil in which these carbonates of soda (reha) abound, are more unmanageable than those in which nitrates abound:  they tell me that, with flooding, irrigating, manuring, and well ploughing, they can manage to get crops from all but the soils in which this reha abounds.

The process above described, by which the bracelet makers extract the carbonates of soda and potash from the earth of the small, shallow tanks, is precisely the same as that by which they are brought from the deep bed of earth below and deposited on or near the surface.  In both processes, the water which brings them near the surface goes off into the atmosphere in a pure state, and leaves the salts behind.  To make soap from the reha, they must first remove the silex which it contains.

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.