'Transactions of the Bombay Geographical Society, from September 1850 to June 1852. Edited by the Secretary. Volume X.' [‎231] (364/458)

LATERITE.
for a lime, ^
cess of ablution, \i
principle of capl;
r is drawn up frit
osphere wliile Ik a
the first rain tliatk
e grand magazine In
i masses for tie es!;
jli but for the salW
le of animal eiislfit 1
'ate of soda, aclif
hrougli the usual 1'
so
soluble W
ices on the carl
and cari
utility)
elation O 11 ® 91
t imf
231
3 new mineral selenite or gypsum of great beauty and utility, and which
results from the destruction of salts inimical to life and vegetation (tho sulphates
of soda, and magnesia) comes into existence. It seems not impossible that to
the decompositions the extreme bitterness of most of the wells of the desert is
due. They taste much more of the muriate of magnesia and tho bittern of tho salt-
makers* than of a solution of muriato of soda.
NOTE D, p. 194,
LATERITE.
I have had repeated occasion to allude in the text to tho rock called latent©*'
and as no description of this most mysterious formation has over been published in :
any of our Bombay Journals, though the rock itself abounds in the Presidency The name given to each of the three divisions of the territory of the East India Company, and later the British Raj, on the Indian subcontinent. ,
I take the following account of it by Captain Newbold, from tho Journal of
the Iloyal Asiatic Society, of London.
I must at the same time state my entire dissatisfaction—with all the theories of its
formation hitherto offered—the whole seems buried iu impenetrable mystery.
“ This rock derives its name Lateritis, (bestowed on it by Francis Buchanan,)
from its being cut into the form of bricks, and used as such by the natives, who
term it often in their own dialects the brick'-stone* Buchanan* identifies it with
the Argilla lapedia of Wallerius.
‘•The laterite varies much in structure and compositionbut, - generally
speaking, it presents a reddish brown, or brick coloured, tubular, and cellular clay,
more or less indurated, passing on the one hand into a hard, compact, jaspideous
rock, and on the other into loosely aggregated grits or sandstones, as at Bey poor
near Calicut, Pondicherry, &c.» and into red sectile clays, red and yellow oohro
and white porcelain earth, plum-blue, red, purplish, and variegated lithomarges.
Sometimes it presents the character of a conglomerate containing fragments of '
quartz, the plutonic, hypogene, and sandstone rocks, and nodules of iron oro
derived from them, all imbedded in a ferruginous clay.
“ The cavities are both vesicular, tubular, and sinuous; sometimes empty, but^
in the lower portions of the rock, usually filled, or partially filled with the earths *
and clays above-mentioned, or a siliceous and argillaceous dust often stained by*
oxide of iron. A species of black bole, carbonized wood, and carbonate of lime,.
sometimes occur* but rarely, iu these cavities* Minute drusy crystals of quartz not
uncommonly line the interior-
“ The walls separating the cavities are composed of an argillosiliceous paste,
often strongly impregnated with iron, and frequently imbedding gritty particles o£
quartz. The oxide of iron prevails, sometimes to such an extent as to approximat©
a true ore of iron, and the nodules are often separated and smelted by the natives
in preference to using the magnetic iron ore, which is more difficult to reduce, frotn
its greater purity. When the whole mass is charged with iron, and very vesicular,
(not unfrequently the case,) it might easily be mistaken for iron slag. The colour
of tho parietes separating the tubes and cells, which in the less ferruginous
* Journey through Mysore, Cimara, and Malabar, Vol. II., pp t 436 and 440*