CHEMICAL SCIEXCE. 203 



of caustic potash and a little sulphuric acid. As soon as the ozono- 

 scopic paper becomes blue, the odor of ozone is perceived, and the gas 

 may be removed by the ordinary modes. 



The Composition of Ozone. Comptes Rendus, No. 14, 1863, con- 

 tains an important paper on ozone, by M. J. L. Soret, presented to 

 the French Academy by M. Regnault," in which, amongst other facts, 

 he states that if ozone is destroyed by heat, by bringing a platina spiral, 

 passed up into a globe containing ozonized oxygen, to a dull red heat, 

 the volume of oxygen is considerably increased, while a very slight in- 

 crease takes place in oxygen that has not been ozonized. For this 

 and other reasons, the writer regards ozone as composed of more than 

 two atoms of oxygen. M. Soret observes that many chemists regard 

 oxygen in its ordinary gaseous state as composed of two atoms, oo, and 

 he says we may conceive molecules of ozone to consist of three atoms 

 of oxygen, ooo, and to constitute a binoxide of oxygen. He thinks it 

 may contain more than three atoms of oxygen, but to determine the 

 exact number its density should be known. 



Ozone as a Disinfectant. Dr. Delabrousse recommends the manu- 

 facture of ozone in the wards of hospitals, for the purpose of their dis- 

 infection. " What we want is," he says, " a proper supply of ozone that 

 is, of a body which is capable of decomposing, and so of neutralizing, 

 the miasms constantly arising in hospital wards, and which at the same 

 time is not hurtful to the patients." And thus, he tells us, the problem 

 is solved. Ozone is such a body, and may be thus used. A spiral 

 platinum wire is placed beneath an inverted funnel, and is rendered 

 incandescent by means of Bunsen's pile. Hereupon the characteristic 

 smell of ozone is perceived in the heated air circulating above the fun- 

 nel ; and its presence is shown by the test paper. Thus may we obtain 

 a ready and practical supply of ozone, and so insure the disinfecting 

 of our hospital wards. British Med. Jour. 



ABSORPTION OF GASES BY CHARCOAL. 



The absorption of gases by charcoal is the subject of a paper by 

 Dr. R. Angus Smith (so eminent for his method of testing the purity 

 of the atmosphere), in a recent number of the Proceedings of the Royal 

 Society. His observations show that-- 1. Charcoal absorbs oxygen so 

 as to separate it from common air, or from its mixtures of hydrogen and 

 nitrogen, at common temperatures ; and, 2, that charcoal continues this 

 absorption for at least a month, although the chief amount is absorbed 

 in a few hours, sometimes in a few seconds, according to the quality of 

 the charcoal. 3. It does not absorb hydrogen, nitrogen, or carbonic 

 acid for the same period. 4. Although the amount absorbed is some- 

 what in the relation of the condensability of the gases by pressure, this 

 is not the only quality regulating the absorption of oxygen at least. 

 5. When it is sought to remove the oxygen from charcoal by warmth, 

 carbonic acid is formed, even at the temperature of boiling water, and 

 slowly even at lower temperatures. 6. Charcoals differ extremely in 

 absorbing power and in the capacity of uniting with oxygen, animal 

 charcoal possessing the latter property in a greater degree than wood 

 charcoal. 7. Nitrogen and hydrogen, when absorbed by charcoal, dif- 

 fuse into the atmosphere of another gas with such force as to depress 

 the mercury three-quarters of an inch. 8. Water expels mercury from 



