SCIENTIFIC SUMMARY. 
283 
oxygen for about a month. 3. It does not absorb hydrogen, nitrogen, or 
carbonic acid for the same period. 4. The quantity absorbed does not 
entirely depend on the condensibility of the gases by pressure. 5. At the 
temperature of 212° Fahrenheit, the oxygen leaves the carbon as carbonic 
acid. 6. Animal charcoal is a more powerful absorbent than wood char- 
coal. 7. When nitrogen and hydrogen are absorbed by charcoal, they 
diffuse into the atmosphere another gas, with a force sufficient to 
depress the mercury three-quarters of an inch. 8. The action of porous 
bodies is not indiscriminate, but elective. — Philosophical Magazine, No. 17 5. 
A Substitute for Bisulphide of Carbon Prisms. — In a late number of the 
Chemical News , a correspondent, alluding to the newly-discovered mer- 
curic-methyl which Dr. Frankland exhibited at one of the meetings of the 
Chemical Society, suggests its employment, instead of bisulphide of carbon, 
in the preparation of fluid prisms. We think the idea most valuable and 
original, and hope, if the thing is possible, to see the suggestion carried out. 
Mercuric-methyl has a high refracting index, a density so great that flint 
glass will float upon its surface, and withal it is not, like the bisulphide of 
carbon, exceedingly volatile. 
Spectrum Analysis of Casium. — In the course of the controversy which is 
now being carried on between Professor Bunsen on the one hand, and 
Messrs. Johnson and Allen on the other, the former states that the method 
of separation of csesium from lepidolite employed by the latter, though 
successful, could not be used when the percentage of the metal was small. 
There is a close correspondence between the results of the analyses of both 
German and English chemists ; and although there were some apparent 
discrepancies in regard to the lines seen in the spectrum, these have been 
now disposed of. Bunsen admits that in one of his plates a few lines were 
introduced which were never seen during experiment, and whose existence 
was owing to a mistake of the printer. In other respects, there is a close 
accordance between the spectra of both chemists, as will be seen by the 
subjacent table : — 
The relation thus expressed between the two series is maintained down to 
the number 1G0 of the American scale, which corresponds to 110 of 
Bunsen’s. Professor Bunsen also states that he and Kirchoff have observed 
the greater number of the supposed new lines of Messrs. Allen and Johnson, 
but owing to the difficulty of reproducing them they were omitted. It is 
not easy to distribute the shades of many of the weaker colours in chromo- 
lithographic printing. See the Philosophical Magazine for October ; and the 
American Journal of Science and Art , vol. xxxv. p. 94. 
Properties of Electro-deposited Antimony. — Mr. George Gore still 
continues his experiments on this subject. In a valuable contribution 
to the Chemical News for November 28, he states that when a 
current of electricity is passed from two or three elements of Smee’s 
Readings on scale of lines seen 
by Johnson and Allen. 
Same as seen by Bunsen, 
75 
80 
82*5 
... 25 
... 30 
... 32*5 
