212 
CORUNDUM. 
facture indeed seemed to be confined to utensils of wood, not better 
varnished than the common tea chests sent to this country. 
I have already had occasion to mention the skill of the Chinese in 
cutting the hardest stones, in describing a vase of exquisite workman- 
ship which I found in a shop at Tien-sing. At Canton I had an 
opportunity of ascertaining their capability of hollowing them, in a 
manner quite enigmatical to European workmen. Of these the snuff 
bottles of rock crystal and of agate were amongst the most puzzling. 
I have one of each of these now before me, which, through openings 
in their neck not the fourth of an inch in diameter, have been worked 
into the perfect hollows of glass smelling bottles. 
The Chinese possess a peculiar facility for cutting stone, in the 
large quantities of adamantine spar or corundum which are found in 
their shops, and which came, they said, from the neighbourhood 
of Canton. That they have it near at hand and of easy access, is 
probable from its profusion, and the low price at which they sell it. 
For a Spanish dollar I obtained as much as I chose to accept. The 
only opportunity that I obtained of seeing it used was in the manu- 
facture of lenses made for spectacles, and which are formed from rock 
crystal, with the assistance of powdered corundum, and a bow with a 
steel thread. The workman fixes a mass of the crystal, which he has 
previously worked into a cylindrical form, over a small trough of 
water firmly before him; and having besmeared the surface of it with 
the powdered corundum made into a paste with water, cuts it into 
laminae by the continued action of the bow, which he assists by 
adding fresh portions of the corundum paste, and moistening the 
crystal with water from the trough. The rough segments thus ob- 
tained are afterwards ground into lenses of different degrees of con- 
vexity, but according to no certain rule. 
In the shops of porcelain at Canton, in all respects inferior to those 
we had seen at Nan-chang-foo, I in vain endeavoured to obtain the 
materials used in its composition. I had no reason however to sup- 
pose that the corundum, as has been suspected, is one of them. Of 
the other ingredients, the kaolin is well known to be the porcelain 
