558 Scientific Proceedings, Royal Dublin Society. 
worthy of future investigation. A comparison of the geology of 
Borneo with that of India may also prove productive of interesting 
results in this respect. 
But the incorrect conclusions of the earlier writers, drawn from 
imperfect data, which I have noticed above, as to the age of the 
diamond-bearing strata in India, afford a sufficient warning of the 
danger of premature attempts at correlation. 
ORIGIN OF THE DIAMOND. 
The examination of the diamond-bearing strata of India has 
not resulted, so far as I know, in throwing any definite ight on 
the yet unsettled question as to the conditions under which the 
crystallization of carbon took place, thus forming the precious 
gem which has occupied so important a position in history. Light 
regarding the subject seems to be destined to reach us indeed 
from another quarter, and it is to the synthetical operations of the 
laboratory, which it is needless to point out have made such 
great advances in this direction of late years, that we must look 
for the true explanation. 
But the absence of any clear evidence on the subject may be 
due to the fact that it is still a matter of doubt whether in any 
single recorded case in India a diamond has been found in its 
original matrix. The lowest diamond-bearing stratum, at the 
base ot the Karnul series, is itself a detrital conglomerate, and it 
is not unreasonable to suppose that the diamonds may, like the 
other ingredients, have been derived from some older metamor- 
phosed rocks. 
Mr. Kine* discusses some apparent cases of mines in the Ka- 
dapah series of rocks which underlie the Karnuls, but he says * 
there is “ still a doubt as to whether true rock-workings in these 
beds were ever successful.” 
Elsewhere, l.c., p. 101, however, he states of the diamonds shown 
to him at Banaganpilly that— ‘ 
“‘ Nearly all the specimens were more or less perfect modifications of 
the octahedron, with curved facets, one of them had each of its facets 
crowned with a little pyramid of tables. 
* Memoirs of the Geological Survey of India, Vol. viii., p. 88. 
+ Strangely enough, Newbold speaks of the diamonds shown to him at the same locality 
as being “ but imperfectly crystallized.”__J. R. A. S., Vol. vii. 
