Chemistry and Physics. 83 



After drying in a vacuum the substance showed the composition 

 corresponding to the formula, KET2Co3(CN)^^ . H^O. The sub- 

 stance, after drying, slowly dissolves in water at 60°, but leaves 

 only a varnish upon slow evaporation. The solution gives pre- 

 cipitates with the salts of most of the metals. The silver and 

 barium salts, thus produced, gave results upon analysis corre- 

 sponding to the formula Ag3Co3(CN)jj . H^O and BaHCo3(C]sr)^j . 

 l^H^O. — Berichte, xxix, 1020. h. l. w. 



6. The substitution of various substances in the place of the 

 water of zeolites. — Geoeges Fkiedel has shown that the water 

 of certain zeolites can be replaced by ammonia. He found also 

 that hydrogen sulphide is absorbed with great energy by dehy- 

 drated chabazite and harmotome, giving, after long exposure to 

 the gas, an increase in weight greater than that of the water lost. 

 The product lost hydrogen sulphide when exposed to the^free air, 

 taking up water and returning to its original condition. Car- 

 bonic acid acted with the same species in the same way. Ethyl 

 alcohol was absorbed slowly but abundantly. Hydrogen was 

 condensed by them very rapidly, but its loss was so rapid that no 

 accurate weights could be made. Finally the author has made 

 an observation which is of great importance to the analytical 

 chemist, viz : that atmospheric air is absorbed so abundantly as 

 to render inexact the determination of water by simple loss by 

 ignition, at least unless fusion takes place. Chabazite absorbed 

 in a desiccator in a few minutes a quantity of air amounting to 

 1*77 per cent of its weight. The presence of this air was easily 

 shown by putting the dehydrated material in a tube filled with 

 mercury, then adding a few drops of water, when the crystals 

 fell to powder and discharged a large volume of gas. This air 

 when analyzed showed the existence of only about 8 per cent of 

 oxygen, and it was, therefore, very difierent in composition from 

 ordinary air. — Compt. Mend., cxxii, 1006.. h. l. w. 



7. Elementary Treatise in Electricity and Magnetism.^ founded 

 on Joubert's "Traite Elementaire d' Electricite," by G. C. 

 Foster and E. Atkinsoj?, 552 pp., London, New York and 

 Bombay, 1896 (Longmans, Green & Co.). — The Elementary 

 Treatise of Joubert is well known for its highly clear and syste- 

 matic presentation of the fundamental principles of electricity 

 and magnetism. This excellent work is now made available for 

 the use of the English-speaking public in general, and in accom- 

 plishing this the editors have performed an important service to 

 English and American students. The present work is, however, 

 more than a translation, for the English editors have to some 

 extent modified the method of presentation, in particular as 

 regards the introduction of the method of viewing electrical 

 phenomena originated by Faraday and developed by Maxwell. 

 They have thus throughout made use of the conception of lines 

 and tubes of force, also of the charge of an electric field as a 

 whole rather than that of the conductors on whose surface the 

 charge appears. They have also simplified the work for the 



