Description of the Petrifaction Ponds at Shirameen. 413 
We selected the best French stones in the mill, made by the 
late Mr. Gardiner, of Liverpool, who was very famous for his 
knowledge of French buhrs; and, that the experiment might be 
the more accurate, we did not grind a quarter of wheat on each 
pair of stones, as it is impossible to part it from the wheat that 
precedes and succeeds with that degree of nicety that is required, 
without running the stones empty and thereby injuring them 
very considerably. But we weighed 480 pounds of meal, ground 
by each pair of stones, from the same wheat, weighing 57 pounds 
the bushel. These two parcels, after remaining a week, were 
weighed again, to see if any accession or diminution of weight 
had taken place; but the weights were precisely the same as 
before. The two parcels of 480 pounds each were then dressed, 
and the result was as follows: 
Flour from the Halkin buhrs ... .. =... 390 pounds, 
Flour from the French buhrs .. .. .. 384 
Difference in favour of the Halkin buhrs 6 
Now, in this experiment, the velocity and work of the stones 
being the same, the quality of the buhrs may be as justly in- 
ferred from the effects, or quantity of flour produced, as any 
other cause in philosophy from its effects. 
We remain, sir, &c. &c. 
J. & W. Pituine. 
LXXXII. Description of the Petrifaction Ponds at Shirameen, 
(a Village near the Lake of Ourmia, in Persia,) which pro- 
duce the transparent Stone known by the Name of Tabriz 
Marble*. 
yee natural curiosity consists of certain extraordinary ponds, 
or plashes, whose indolent waters, by a slow and regular process, 
stagnate, concrete and petrify, and produce that beautiful trans- 
parent stone, commonly called Tabriz marble, which is so re- 
markable in most of the burial-places in Persia, and which forms 
a chief ornament in all the buildings of note throughout the 
country. These ponds, which are situated close to one another, 
are contained in a circumference of about half a mile, and their 
position is marked by confused heaps and mounds of the stone, 
which have accumulated as the excavations have increased. We 
had seen nothing in Persia yet which was more worthy of the at- 
tention of the naturalist than this, and I never so much regretted 
my ignorance of subjects of this nature, because I felt that it is of 
* From Motvier's Travels in Georgia, Persia, &c. ; 
consequence 
