Natural History. » 453 
that the green ore of uranium from Cornwall contains phos- 
phoric acid, and not merely the oxide of uranium and copper 
combined with water. 
10. Porcelain Clay—Gold in Cheshire.—A superior clay, 
said to be well adapted for the manufacture of the best sort of 
china, has recently been discovered on the estate of Mr. Acker- 
ley, at Little Saughall, near Chester. This clay is now in pro- 
gress of trial, and it is expected that a pottery will soon be 
established on the place. It is stated also that Mr. Ackerley 
procured small grains of gold, from some of the strata through 
which he has penetrated in search of coal. 
11. Coal Seam.—A seam of coal, six feet three inches in 
thickness, was come at lately in the new colliery at Helton, at 
a depth of 654 feet. It is to be hoped the owners of the col- 
liery will find in it a reward for their perseverance and exertions. 
12. Inoculation and Vaccination.—Daniel Bernouilli cal- 
culated that the inoculation of the small-pox has been the 
means of prolonging human life by three years, and the new 
observations of Duvillard gave the same result from vaccination. 
13. Fracture of Calculi in the Bladder.—An instrument has 
been invented, and, it is said, brought to perfection in Paris, by 
M. Amusat, the use of which is to break down calculi in the 
bladder, and render the fragments so small that they may be 
voided as gravel. The instrument consists of pincers which aré 
confined in a tube not larger than a sound, until introduced into 
the bladder. They are then opened, the stone is seized with 
facility, and by moving the handles in a particular manner, is 
soon reduced to powder. In a few seconds, a stone the size of 
a nut is broken with facility; it appears, however, that as yet 
the trial has been made only on a dead body. It still remaims 
to be learned what the result will be in a living one. 
14. Prussian Travellers—The Prussian naturalists, Drs: 
Ehrenberg and Hemprich, in their tour in the interior of Nor- 
thern Africa, arrived safely at the celebrated Dongola, the capi- 
tal of Nubia, on the 15th February. These zealous collectors 
have sent six remittances to Berlin, and have again accumulated 
more than they can pack in 20 chests. Their collection con- 
sists of mammalia, birds, amphibia, insects, plants, and, what 
are more rare, fishes and insects of the Nile. 
15. New Series of the Geological Transactions.—The Geolo- 
