CHEMISTRY. 259 



bons, and lias contrived an ino-enious method for conducting 

 the manipulations under water, so that the operator is not 

 annoyed by the fumes of the bromine. The results obtained 

 are accurate. 



Berthelot has discovered a new oxide and acid of sulphur, 

 produced by the action of the silent electric discharge upon 

 a mixture of sulphurous oxide and oxygen gases in his im- 

 proved ozonizer. The oxide appears in long silky needles 

 somewhat resembling sulphuric oxide. Its formula deter- 

 mined by various methods is S 2 7 , and hence the discoverer 

 names it persulphuric oxide. It is soluble in concentrated 

 sulphuric acid without decomposition, forming persulphuric 

 acid. Its barium salt is soluble in water. The acid is also 

 produced directly by the electrolysis of sulphuric acid, or by 

 mixing oxygenated water with concentrated sulphuric acid. 

 Indeed, the oxidizing substance produced in ordinary electrol- 

 ysis, and hitherto supposed to be either hydrogen peroxide 

 or ozone, is really persulphuric acid, proved both by its pos- 

 itive and its negative reactions. 



Buchanan, chemist of the Challenger expedition, in his anal- 

 yses of sea-water, observed the curious fact that from the sur- 

 face down to 300 fathoms the oxygen continuously decreases 

 in amount, while below 300 fathoms it continuously increases. 

 This is due to the scarcity of animal life at the greater depths. 



Pasteur has recently stated that water containing bacteria 

 and all water, even distilled water, contains them, and can 

 contaminate any cultivation liquid with a growth of them 

 if allowed to stand for several w T eeks at a constant tempera- 

 ture, becomes purer in its upper portions, the bacteria settling 

 to the bottom. Dowdeswell has repeated the experiment, 

 and though the water w r as perfectly clear and bright in ap- 

 pearance, the sediment showed under the microscope amor- 

 phous particles, spores of filamentous fungi, micrococci in 

 great numbers, bacteria of the common form, and bacilli in 

 Ioiigj slender filaments. 



Gatehouse has proposed a new method for the preparation 

 of nitrogen gas by the reaction of manganese peroxide upon 

 ammonium nitrate. In one experiment three grams of the 

 nitrate, heated with an equal weight of manganese peroxide 

 in a mercury bath kept at 205 C, yielded 630 cubic centim- 

 eters of gas, which was pure nitrogen. If the temperature 



