Dr Anderson on the Strata of the Diamond Mines 
Art. XI. — Account of the Strata at the Diamond Mines of 
MallivuUy, By the late Dr James Anderson of Madras. 
.1. HE following account of the strata at the diamond mines of 
Mallivully in the Mustaphanagur Circar, was found among the 
papers of the late Dr James Anderson of Madras, by his ne- 
phew Dr Berry. It had been drawn up for the Asiatic Society, 
but it appears either never to have been sent to that body, 
or never to have been published in their Transactions. 
So early as the year 1767, Dr Anderson had received speci- 
mens of the earth and stones found at different depths in these 
diamond mines, and having, thirty years afterwards, obtained a 
still more complete series of specimens, he was struck with the 
correspondence between the two sets, and drew up the following 
accouDt of them. 
The specimens which he received in 1767 were as follows : 
(a.) Fine grained white lime, in roundish and sometimes an- 
gular lumps, agglutinated with some small pieces of whitish 
quartz, roundish stones of deep red ochre of iron, and light yel- 
low ochre adhering. It is said that the diamonds are found ad- 
hering to this stony mass, and beat off by knocking two pieces 
of it together, 
(d.) A tophous stone, consisting of fat yellowish iron-clay, 
talcky small quartz, and calcareous earth conglutinated. 
(<?.) Whitish fat quartz. 
(d.) Small stones which have been knocked off as above 
mentioned, washed by a run of water, and searched for dia- 
monds. 
(e.) The sandy sediment washed from the foregoing small 
stones, of a yellowish colour and ochrey appearance. 
W, B. The calcareous earth and ochrey part of the sediment, 
effervesce in the nitrous acid. 
The specimens of the different strata of earth and stones of 
the diamond mines at Mallivully, which Dr Anderson received 
in 1797, were as follows : 
No. 1. Strata three feet from the surface, is porous, of a dirty 
red colour, intermixed with a few particles of white quartz. 
