440 
rOPULAR SCIENCE REVIEW. 
time being fixed for January 1, 1871. Apply to the Mineralol-Verein zu 
Halle a. d. S. Prussia. The committee of examination consists of several 
parties, among whom is M. A. Riebeck, at Halle. 
Mineralogical Work . — The American Journal of Science and AH (July), 
gives a long account of several new mineralogical discoveries of Mr. C. U. 
Shepard, sen. They are summed up as follows : A new variety of colum- 
bite, found to consist, in 100 parts, of metallic acids, 78-30 ; protoxide of 
iron, 13 86 ; protoxide of manganese, 7-72 ; traces of tin. Unknown mineral 
(microlite ?) in Haddam columbite. New locality of bismuthine and bis- 
muthite, in Haddam. Metallic acid in microlite. Redondite, a mineral 
found in Redonda Island, and containing 44 07 per cent, of phosphoric acid, 
24*73 per cent, of water, and oxide of iron and alumina. Phosphoric acid 
in the diaspore of Chester, Mass. ; the mineral here alluded to is mainly 
hydrate of alumina, containing only 0 32 per cent, of phosphoric acid. The 
Pelham vermiculite contains, in 100 parts, alumina, 14-0 ; magnesia, 13-68 ; 
peroxide of iron, 32-0 ; silica, 24-0. 
The Khettree Meteorite . — The Chemical News of June 17 contains a very 
long account, by Dr. Waldre, F.C.S., of this peculiar meteorite, which seems 
to have fallen very largely. The stone is partly of a light bluish-grey 
colour, partly of a much darker grey ; in some places the two portions lying 
in contact like two strata, in others nodules of the one imbedded in the 
other. The broken surface is studded over with metallic particles, many of 
them having a bright metallic lustre; and there are also observable, by aid 
of a lens, spots of a yellowish or brown colour, from oxidation of the iron, 
and granules of a greenish-yellow colour and translucent appearance, pro- 
bably olivine. Spherules of earthy matter are also visible, and round 
cavities in which others have been imbedded. When coarsely powdered, 
the spherules are more visible ; and, when more finely powdered and ex- 
amined under water with the lens, the lighter portion of the stone exhibits a 
considerable quantity of a nearly white crystalline matter, the particles of 
which are tolerably uniform in size, mixed with small angular fragments of 
black, brownish, opaque, and greenish -yellow translucent minerals, and 
irregularly-shaped but rounded particles of iron. The dark grey portion 
exhibits the same appearances, but with a much larger proportion of dark- 
coloured earthy minerals. The particles of the iron, having resisted tritura- 
tion, now appear much larger than the others. 
The Action of Heat on Diamonds . — A very curious influence exerted by 
heat upon diamonds has been noticed at the works at St. Helen’s, recently 
visited by the British Association. When a diamond is used to cut hot 
glass the diamond will only last for one day, and it assumes a milky appear- 
ance. The diamonds in constant use for cutting cold glass last about three 
months. Each diamond costs from 3 5s. to 45s., and is about three times 
the size of an ordinary glazier’s diamond. Hot glass is cut more readily 
than cold glass. 
Improvements in Heavy Forgings. — Lieut.-Colonel Clay read a short paper 
on improved appliances for the production of heavy forgings at the Liver- 
pool meeting of the British Association. Considerable difficulty had until 
recently been encountered in the economical forging of large solid masses of 
iron, which was an engineering desideratum of vast importance. The old 
