248 M. Kovanko's General View of the Environs of Pekin. 
powder ; it is in this form that it is used to complete the pro- 
cess of cleaning the rice. Its texture has not the appearance 
of being foliated, but it is always divided by a great number 
of fissures into irregular masses, which renders the quarrying 
of it very difficult.* 
The limestone, in a half decomposed state, containing a 
great quantity of white sand, enters into this formation in 
subordinate beds. In some places this limestone decomposes 
to such an extent as to form a white powder which covers the 
whole surface. 
Sandstone, small grained, of a dark colour, traverses this 
formation also in beds, which alternate occasionally with those 
of the predominating rock. These beds of sandstone have 
only a thickness of 1 or 2 archines. 
The porphyry, which rises in the form of a mamelon, near 
the temple of Ba-or-Sy, three li to the north-west of that of 
Loun-Tzouan-Sy, appears to have had some influence in the 
formation of this dolomite. 
This porphyry, of a deep red colour, gives out a strong 
smell of clay. It has but little consistence, and its surface is 
fissured all over. 
The ferruginous red sandstone, which is divided into rhom- 
boidal faces by joints, ought likewise to be classed as belong- 
ing to the dolomite formation. It does not constitute any con- 
siderable masses, and is only found lying on the flanks of 
the compact dolomitic limestone. The sandstone, in decom- 
posing, forms an excellent soil for cultivation. 
One li to the north-west of Loun- Tzoun-Sy, a small outcrop 
of a chloritie slate, having a coarsely foliated structure, is 
seen bordering upon the dolomite, which disappears almost 
entirely under alluvial clay. Its dip is very highly inclined, 
the beds being very irregular and singularly contorted. Some 
traces of lime are found in it, but no other minerals. 
The Western Mountains, as has already been said, are com- 
* Note by the Author.—-About 6 francs (French money) are paid for the 
extraction of 150 pouds of this rock. The carriage of 15 pouds to the ca- 
pital, distant 60 li, costs about 60 francs. 
