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POPULAK SCIENCE KEYIEW. 
A Battery which works for Years lias been invented by HeiT Boettger. 
It retains its activity for several years^ and is admirably adapted to the 
working of electric clocks, ringing electric bells, and the requirements of 
olectro-metallurgy.. Each cell consists of a cylinder of thick plate zinc en- 
closed in a glass jar. In the centre of the cylinder is placed a bar of compact 
coke, and the intervening space is packed with a powder composed of a 
mixture of equal volumes of pounded sulphate of magnesia and common 
salt, moistened with a saturated solution of these two substances. The salt 
mixture is moistened from time to time, and the zinc of one cell carefully 
combined with the coke of the next, according to the usual method. — Vide 
The Artizan, January. 
The Temperature of Gaseous Flames . — In a late number of PoggendorfiTs 
Annalen, Herr Bunsen publishes a paper on the temperature of the flames of 
carbonic oxide and hydrogen, which is worthy of the notice of physicists. 
Among other interesting points, the author states that a mixture of carbonic 
oxide and oxygen, in the proportions proper for combustion, will be heated 
from 0° to 8033’ centigrade; of hydrogen and oxygen, from 0° to 2844° 
centigrade ; a mixture of carbonic oxide and air, from 0° to 1997° centigrade ; 
and a mixture of hydrogen and air from 0° to 2024° centigrade. 
The Lamellar Polarization of Alum . — In a paper read before the Academy 
of Sciences of Berlin, Herr Beusch discussed this very interesting pheno- 
menon. He thinks that the polarisation is as supposed by Biot — partly 
due to the fact, that the crystal is made up of a multitude of small octahedra, 
and that these not being in immediate contact, they act in the same manner 
as a polarising bundle of glass plates. But he says this by no means explains 
the whole of the phenomena, and hence he feels compelled to admit that 
the crystal has in a slight degree the power of double refraction. — Vide 
F Institut, March 18. 
The Interference of Sonorous Waves rendet'ed Visible. — Herr Stefan has 
described an ingenious apparatus for this purpose. The account is published 
in a paper presented to the Academy of Vienna, and is given in abstract in 
FInstitut of February 19. 
ZOOLOGY AND COMPAEATIVE ANATOMY. 
A New Species of Monkey. — At the meeting of the Zoological Society, on 
the 27th of February, Dr. J. E. Gray, F.B.S., read a description of a new 
species of monkey of the genus Colobus, from Zanzibar. The species had 
been discovered by Dr. J. Kirk, and had been forwarded by him to the 
British Museum. Dr. Gray therefore proposed to call it C. Kirki. 
The Fevelopment of a Dragon-Fly. — The development of a species of 
dragon-fly (genus Diplax) has been very carefully worked out, and has been 
duly described and admirably figured by Dr. A. S. Packard, Jun., in a 
paper read before the American Association for the Advancement of Science. 
The paper has been published in the American Naturalist for February, 
and it is well worth attention. 
Parallelism of Fore and Hind Legs of Vertebrates. — In the Journal just 
