Chemistry and Physics. 845 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. On a new Gaseous Constituent of the Atmosphere. — At the 

 recent meeting of the British Association at Oxford, Lord 

 Ratleigh announced that in conjunction with Professor Ramsay, 

 he had succeeded in isolating from atmospheric air a new gaseous 

 substance. His experiments on nitrogen had shown that the 

 density of this gas varied considerably according to the source 

 from which it was obtained. Supposing this to be due to a 

 variable mixture of some other and unknown gas, he added to 

 the air an excess of oxygen and passed through it an electric 

 discharge. The density of the nitrogen gradually increased and 

 finally reached 19*8. Ramsay operated by removing the 1 oxygen 

 from air and then passing the nitrogen over heated magnesium, 

 which was thereby converted into nitride, leaving a residual gas 

 having a density of 20*8. It is thus more inert than nitrogen. 

 It exists in the air to an amount of one per cent and has some 

 peculiarities in its spectrum. Its elementary character is yet in 

 doubt, Professor Dewar suggesting that it may turn out to be 

 an allotropic form of nitrogen. G. f. b. 



2. Die wissenschaftlische Grundlagen der analytischen Chemie; 

 by W. Ostwald, Leipsic (Engelmann), 1894. 12mo, viii + 187 

 pp. Price 4 marks. — The appearance of each new work by 

 Professor Ostwald causes astonishment at the remarkable fertility 

 of his pen. The present book is an elementary treatise on ana- 

 lytical chemistry, written especially from the standpoint of the 

 new theories of solutions. A very clear exposition of the theory 

 of ions and the laws of chemical equilibrium is given, and from 

 these some general laws and rules, applicable to chemical analysis, 

 are derived. These rules are suggestive and they give a satis- 

 factory explanation of certain well-known facts which heretofore 

 have been somewhat empirical. The larger part of the book is 

 devoted to a systematic classification of the ordinary analytical 

 operations, and to a description of well-known methods. It 

 must be said that not all of the latter are the most recent or the 

 best of their kind, but the intention of the author has not been 

 to furnish instruction to beginners, but to give an example of his 

 method of treating the subject, based on the idea that nearly all 

 analytical reactions are ion reactions. 



The author criticizes the usual practice of inorganic analysts, 

 of giving results in terms of metallic oxides and acid anhydrides, 

 as being based on antiquated chemical ideas, and he objects 

 especially to the customary way of " combining " constituents in 

 analyses of mineral waters and other solutions. He advocates 

 the statement of analyses in terms of the elements, or, in the case 

 of solutions, in terms of the ions. It seems probable that, for the 

 sake of simplicity of calculation and easy comparison with pre- 



