28 doreign Notices in Mineralogy, &e. 
work, “ on the Formsof the Inorganic Kingdom,” of which 
the first part will appear next Easter, and the second the 
following summer. Having finished this interesting work, 
he will next prepare and put to press, an account of his 
geognostical investigations in the Alps and in Italy.” 
“ Extraordinary mass of Platina discovered in Peru.— 
A negro slave in the gold mines of Condoto, in the govern- 
ment of Choco, in South America, found a mass of platina 
of extraordinary magnitude, and which. is now deposited in 
the Royal museum, in Madrid. It weighs rather more than 
one pound and a third, and is the largest piece of this metal 
hitherto met with. The largest specimen brought from 
America by Humboldt, and deposited in the King’s cabinet 
in Berlin, and which weighs 1085 grains, was also found in 
Choco. These facts allow us to hope, that platina may be 
found in its original repository somewhere in that country.’ 
Dr. Brewster has given the name Comptonite to a mine~ 
ral brought from Italy, by Earl Compton, (Resident of the 
Geological Society of London.) ‘It is found in small 
transparent or semi-transparent crystals, lining the cavities 
of an amygdaloidal rock from Vesuvius. The crystals are 
right prisms, nearly rectangular, with plane summits; or the 
same figure truncated on the lateral edges, so as to compose 
an eight sided prism. This last form is the raost common. 
Comptonite, by exposing it in the state of powder to the 
action of nitric acid, is convertible into a jelly, like all the 
mesotypes.—It scratches stilbite, fluor spar, and apatite, 
but not mesotype. It is distinguished from stilbite, 
by its being convertible into a jelly by nitric acid, a prop- 
erty not possessed by stilbite. It is distinguished from 
auvergne mesotype, and from the mesotype or needlestone 
of Iceland by the angles of the primitive prism, &c. 
From No.5 of Edinburgh Philosophical Journal. 
* Account of three new species of lead ore found at Lead 
hills; by H. J. Brooxe, Esq. F. R. S. Lond. M. G.S. 
&c. &e. 
Among some specimens of lead ore from Lead hills, I 
have found three new species, of which two have been no- 
