It is
of a darker colour, and forms more into clods to retain moisture. I
may here mention that the Himmalaya chain does not abound in volcanic
rocks, like the chains of Central and Southern India; and that the
soils, which are formed from its detritus, contain, in consequence,
less phosphoric acid, and is less adapted to the growth of that
numerous class of plants which cannot live without phosphates. The
volcanic rocks form a plateaux upon the sandstone, of almost all the
hills of Central and Southern India; and the soil, which is formed
from their detritus, is exceedingly fertile, when well combined, as
it commonly is, with the salts and double salts formed by the union
of the organic acids with the inorganic bases of alkalies, earths,
and oxides which have become soluble, and been brought to the surface
from below by capillary attraction. I may also mention, that the
basaltic plateaux upon the sandstone rocks of Central and Southern
India are often surmounted with a deposit, more or less deep, of
laterite, or indurated iron clay, the detritus of which tends to
promote fertility in the soil. I have never myself seen any other
deposit than this iron clay or _laterite_ above the basaltic
plateaux. I believe that this laterite is never found, in any part of
the Himmalaya chain. I have never seen it there, nor have I ever
heard of any one having seen it there. In Bundelkund and other parts
of Central and Southern India, the basaltic plateaux are sometimes
found deposing immediately upon beds of granite.
Pages:
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360