196 ANNUAL OF SCIENTIFIC DISCOVERY. 



oxide constant!}' takes oxygon from the hypooljlorite of lime, and 

 passes into a hi^rlu-r oxiile, wliich is decomposed into oxyj^en and 

 the lower oxide, and tlie process is then repeated. One-halt" to 

 one-tenth of one per cent, of hyperoxide is sullicient to decompose 

 an indelinite amonnt of the hypochlorite. According to him, the 

 advantages of this method are: 1. The evolution of the gas is 

 very regular and easily managed, so that the process may be 

 used for lecture experiments in which a gas bladder cannot be 

 employed. After llie heat is once applied, the lamp may usually 

 be removed, the deionii)osition going on to the end. 2. All the 

 oxygen of the mati'rial is obtained, whicii is not the case wln^n 

 peroxide of manganese is heated. 3. It is much cheaper than that 

 by means of chlorate of i)otash. — Ann. der Vhemieund I'/iar., 134, Gi. 



OXYGEN OBTAINED FROM ATMOSPHERIC AIR. 



Onr ordinary modes of obtaining oxygen, for experimental and 

 other purposes, are very costly or very trouldesome. It may, 

 however, be procured with great facility through the medium of 

 permanganate of soda, which, as it may l)e uscmI over and over 

 again for the purpose, will entail but a trilling expense. Atmo- 

 spheric air is passed over a solution of the perniaiiganate, which, 

 after a while, becomes saturated with the oxygen it has absorbed, 

 the nitrogen having passed off. To separate the oxygen from 

 the solution, a current of vapor at a proper temperature is substi- 

 tuted for the current of air; this, almost without ])i(>ducing any 

 change in the permanganate solution, further than dilution, 

 causes the oxygen to be evolved. Concentrating the solution by 

 heat renders it again fit for use, especially if a very small quan- 

 tity of the permanganate is added to it. — Intel. Observer, 18GG. 



JAPANESE HAND FIREWORKS. 



Dr. Hoffmann lately exhibited to the London Chemical Society 

 some small paper fuses brought from Japan. They burn with a 

 small, scarcely luminous flame, a red-hot ball of glowing saline 

 matter accumulating as the combustion i)roceeds. When about 

 half of the fuse is consumed, the glowing head begins to send 

 forth a succession of splendid sparks, assuming the character of a 

 brilliant scintillation very similar to that observed in burning a 

 steel spring in oxygen, only much more delicate, the individual 

 sparks branching out in beautiful dendritic ramifications. His 

 first idea was to look for a finely-divided metal in the mixture ; 

 but examination in the laboratory showed that it was quite free 

 from metallic constituents, and contained only carbon, sulphur, 

 and nitre ; these were present in the following projjortious : car- 

 bon, 17.32; sulphur, 29.14; nitre, 53. 04. Each fuse contained 

 about 40 milligrammes of the mixture, folded up in fine pajier. 

 He had easily imitated them. A mixture of carbon, 1 (powdered 

 wood charcoal), sulphur 1^, and nitre 3;^, pi'oduced the phenom- 

 enon in even a more striking manner. Ordinary English tissue 

 paper might be used, but the genuine Japanese paper was far 

 better. 



