Chemistry and Physics. .75 



or potassium osmiochloride in a current of hydrogen, the chlorine 

 being also determined. The ammonium osmiochloride was pre- 

 pared by adding ammonium chloride to an alcoholic solution of 

 osmium chloride. The potassium salt was obtained by heating 

 the metal mixed with potassium chloride in a current of chlorine. 

 A second portion of the ammonium salt was prepared by precipi- 

 tating sodium osmiochloride with ammonium chloride. The 

 results of analysis gave 191*12 as the mean of several experiments. 

 The author thinks this too high and gives 190"8 as the more 

 probable atomic mass. — Ber. Berl. Chem. Ges., xxi, 1839, June, 

 1888. G. F. B. 



6. A Class Book of Elementary Chemistry ; by W. W. 

 Fisher, M.A., F.C.S., Aldricbian Demonstrator of Chemistry. 

 12mo, pp. xvi, 272. Oxford, 1888. (Clarendon Press). — In his 

 preface the author states that, in the main he has followed in 

 his selection of subjects the syllabus of the Oxford Local Ex- 

 aminations for Senior Candidates and the Examination of 

 Women. After a few pages upon the laws of chemical combina- 

 tion, atomic weights and formulas, he takes up hydrogen, oxy- 

 gen, water, nitrogen, air, carbon, sulphur, etc. In chapter xv, 

 he considers quantivalence and the periodic law, and then dis- 

 cusses the metals, closing with chapters on specific, atomic and 

 molecular heats, and the physical properties of gases. It is one 

 of the best books of its grade that we have seen recently. The 

 cuts are clear and well selected and the mechanical execution of 

 the book is good. g. f. b. 



7. Examples in Physics • by D. E. Jones, B.Sc, Lecturer 

 on Physics at the University College of Wales, Aberystwyth. 

 16mo, pp. viii, 261. London and New York, 1888. (Macmillan & 

 Co.). — This little book contains a carefully prepared series of 

 physical problems, over one thousand in number, intended to test 

 both the student's knowledge and his facility of applying it prac- 

 tically. The value of such tests is beyond dispute. The intro- 

 ductory chapter is a concise exposition of units and dimensions, 

 and the subsequent chapters are devoted to Dynamics, Hydro- 

 statics, Expansion, Specific and Latent Heat, Conductivity and 

 Thermodynamics, Light, Sound, Magnetism, Electrostatics, and 

 Current Electricity. We have failed to find at the end of 

 the book, however, the four-place logarithm tables mentioned 

 on pages 19 and 21. The problems themselves are most ex- 

 cellent, many of them being selected from examination papers 

 of repute. The book will be found a valuable adjunct in the 

 physical class room. G. f. b. 



8. Oxygen lines in the Solar Spectrum. — M. Janssen ascended 

 Mt. Blanc on October 13th, and succeeded on October 15th and 

 16th in making some observations under the most favorable con- 

 ditions. The results show that both the band and lines of oxy- 

 gen, identified previously by him in the solar spectrum, are due 

 entirely to the earth's atmosphere. The systems of bands, those 

 in the red, in the yellow, and the blue, the intensity of which 

 varied with the square of the density of the absorbing oxygen, 



