1.8.C. 20  Proes. of the Asiatic Soc. of Bengal. {N.S., XVIII, 
namely, Sub-recent, Pleistocene or perhaps Pliocene, may 
« 
laterite as below it. The question is a big one and might well 
occupy an address in itself, so 1 must be excused from saying 
anything more about it now. 
here is just one more matter of theoretical interest con- 
nected with these recently discovered Jammu bauxites, in 
virtue of the composition of the latter being nearly pure dias- 
pore or mono-hydrate of alumina: this is, the question 
whether the sapphires of Padar in Zanskar, which are known 
to occur ina granite matrix with Nummulitic limestone form- 
ing the craggy heights above, may not owe their origin to 
contamination of the granitic magma with included masses of 
diaspore rock picked up from the infra-nummulitic rocks in 
that region. The idea seems a good working hypothesis, but 
I have had no opportunity as yet of testing it on the ground. 
Gypsum. 
_ _ The last mineral I have selected to say a few words about 
is the gypsum of the Jhelum Valley in the tehsil of Uri. One 
reason why I have chosen this mineral out of several others that 
have an equal or better claim to your attention, is that it— 
exists in such enormous—almost fabulous— quantities. It is 
no exaggeration to say that in the hills and valleys just north 
of Mohura Power Station there lie hundreds of millions of tons 
E. and W. across a number of steep secondary ridges and 
spurs descending from the Kaz-i-Nag range down to the 

