50 Mr H. M. Stoker on the China-stone 
On the China-stone and China-clay of Cornwall. By Mr H. 
M. Stoker, of St Austel, Cornwall. 
(Continued from vol. lvi., p. 102.) 
Kaolin is found intermixed with quartz and scales of mica, 
in most valleys contiguous to the decomposing hills of the 
primary strata of our county, and is not, so far as is at pre- 
sent known with regard to China-stone, confined to any par- 
ticular district, being now obtained or obtainable, though of 
different qualities, on the south-western sides of either of the 
granite districts; yet, of course, poorest near those beds of 
China-stone which I before described as free from most dete- 
riorating substances, as in the parish of St Stephens. 
It exists in these beds or stopes, as they are designated, 
as an amorphous, whitish-blue, opaque powder, which, from 
the softening influence and rainy character of the south- 
westerly winds, are most frequent in valleys situated on the 
same aspect; often lying on the contiguous borders of the 
granite and killas, clay-slate, greywacke or transition strata, 
by which this is surrounded; where, being exposed to the 
action of lodes and co-existing springs, on the occurrence of 
the slightest convulsion, it has slid to the adjacent valleys, 
where its presence is indicated by the generally smooth and 
flattened appearance of the surface,—by the vegetation on it, 
which is often luxuriant, especially if the clay contain an ex- 
cess of potash,—and by the number of springs to which it 
gives rise in the immediate vicinity, their height above the 
level of the sea being necessarily limited by that of the val- 
leys in which the clay is deposited. 
The character of the clay very much assimilates to that of 
the granites from which it has been formed by the disinte- 
grating process to which I referred while speaking of the 
formation of China-stone, not only as to the quantity obtain- 
able from a given amount of clay-stope, but also as to the 
purity of the article and its whiteness, the whitest clay being 
formed from that granite which has the whitest felspar, and 
is most free from iron, the presence of this giving the ma- 
nufactured wares an appearance termed “ foxey;” while, 
