526 Scientific Proceedings, Royal Dublin Society. 
these gold-producing tracts, it is certain that within such limits 
a process of segregation has been going on towards the richest 
points. 
In a part of Western Bengal* I found that generations of 
washers had demarcated limits within which washing was remu- 
nerative, and these limits corresponded in a striking degree to 
the well-defined boundaries between two formations—the meta- 
morphic and the sub-metamorphic. In the area occupied by the 
former, gold was not absent, but its abundance as contrasted with 
that in the latter I ascertained, by two independent methods of 
calculation which are described below, was in the proportion of 
1 to 8. Hence, as the washers only managed to eke out a bare 
subsistence in the sub-metamorphic area, they confined their 
operations to it. 
The detailed accounts of Indian gold-producing tracts admit 
of the following geographical arrangement, proceeding from South 
to North :— 
MADRAS. 
1. Wynaad, and 2. Kolar. 
BoMBAY. 
1. Dharwar, 2. Belgaum, and 3. Kaladgi. 
BENGAL. 
1. Central Provinces, 2. Orissa, 3.S. W. Bengal, 4. N. W. Pro- 
vinces, including Himalayas and Punjab. 
ULTRA-PENINSULAR AREAS. 
1. Assam, 2. Burmah, 3. Afghanistan, 4. Thibet. 
MADRAS. 
Wynaab District.—The recent contributions to the literature 
of the gold fields of the south-eastern portion of the Wynaad are 
so voluminous that I experience a difficulty in preparing a sufli- 
ciently complete epitome of their contents. Among these contri- 
butions the principal are the reports by Mr. Wm. King, jun.,t 
Deputy Superintendent of the Geological Survey of India, and 
Mr. Brough Smyth,t who was specially deputed by the Govern- 
ment of India to explore and report upon the gold in Southern 
India. 
* Vide infra, p. 537. 
+ Records of the Geological Survey of India, Vol. VIII., p. 29, and Vol. XI., p. 235. 
$ “ Report on the Gold Mines of the South-Eastern portion of the Wynaad.” 
