Mineralogy.— Geology. 461 
attaching the cage of platinum wire to the wick. It would ap- 
pear, though the contrary might at first seem to be the case, 
that suspension from the roof of the cylinder was previously con- 
templated by this eminent philosopher: in proof of this, please 
he referred to page 231 of your September Number. The safety 
lamps provided in this manner by Mr. Newman for others and 
myself prove the same thing ; and I have reason to believe that 
those forwarded by Sir H. himself were similarly constructed, 
This remark has been elicited by the plate illustrating Sir H. 
Davy’s interesting paper on flame, inserted in a recent number 
ef your journal. Unless the platinum wire wind immediately round 
the wick, the effect cannot be accomplished, and then it cannot 
be pronounced unequivocal in every case ; my last appendage is 
calculated to supply the desideratum. 
By clearing away the rubbish, I discovered a vein of the ‘* po- 
lishing powder” traversing gneiss. It appeared in joints varying 
in length from one tenth to one inch: the vein was slightly in- 
clined to the horizon ; the silken fibres disposed longitudinally, 
and sometimes having their disposition altered by fragments of 
quartz interspersed with needle schorl, A more minute account 
will appear in my paper on the mineralogy of the Isle of Man, to 
be shortly submitted to the Wernerian Society of Edinburgh. I 
think it intermediate between actinolite and aslestine tremolite. 
I made more minute inquiry respecting the meteorolite of Pulros, 
It fell twenty-five years ago during a tremendous thunder storm, 
burst in its fall, and scattered its fragments over an area of three 
hundred yards in circumference: this space was ploughed up by 
the effects of the lightning in a zigzag manner, and the ridges 
were tinged of a Llueish colour. The animals seem to have been 
killed by the lightning which preceded the descent of the me- 
teoric stone, exhibiting but slight evidence of external injury. 
I have the honour to be, &c. 
Whitehaven, Noy. 2}, 1817. J, Murray. 
GEOLOGY. 
The island of Great Britain presents a richer field for geological 
inquiry than any other country that has yet been examined, 
comprising in a comparatively shorte xtent a succession of all 
theprincipal rocks, from those which have been regarded the 
most ancient to the very newest formations, ‘There is scarcely 
any one species of rock of importance, except those of recent vol- 
cenic origin, that may not be found well characterized in some 
part of our island. Our mineral treasures, too, far exceed in an- 
nual value those of any country on the continent of Europe. With 
these inducements for research, and the great facilities that our 
insular situation affords for the study of geology in the bold 9 
we 
