558 Scientific intelligence. 



Limited). — The first edition of this very interesting book appeared 

 in 1896, soon after the discovery, by Lord Rayleigh and the 

 author, of argon in the atmosphere. It gives the history of the 

 discover}* - of the better known constituents of the air in popular 

 language and in a very entertaining way, and thus leads up to an 

 excellent description of the work on argon. Full-page portraits 

 are presented of the prominent early investigators of the atmos- 

 phere : Hales, Boyle, Mayow, Black, Rutherford, Priestly, Scheele, 

 Lavoisier and Cavendish. The latter had collected argon from 

 the atmosphere and had purified it perfectly more than 100 

 years before Rayleigh and Ramsay named it. Readers of the 

 book will regret that it contains no portraits of the author, of 

 Lord Rayleigh, of Travers, of Madame Curie, of the modern 

 Rutherford, of Soddy, and of other recent discoverers in the 

 domain of atmospheric gases. To the second edition of the book, 

 in 1900, a chapter was added dealing with helium, neon, krypton 

 and xenon. In 1905, the third edition gave an account of the 

 radioactive gases, and this chapter has been extended in the pres- 

 ent edition. There is probably no scientific achievement of more 

 general interest than the explanation of our atmosphere, and the 

 story is admirably told in this book. A considerable amount of 

 instruction in elementary physical and chemical theory is pre- 

 sented for the sake of those who need it, while the historical 

 matter, including the explanation of the curious phlogistic theory, 

 is very suitable reading for students of chemistry and physics. 



H. L. W. 



5. Metallurgists and Chemists'' Handbook. Compiled by Donald 

 M. Liddell. 12mo, pp. 603. New York, 1916 (McGraw-Hill 

 Book Company, Inc. Price $4). — This is a reference book of tables 

 and data which is conveniently and attractively printed and 

 bound with the use of thin paper, gilt edges, and a flexible 

 leather cover. It is divided into sections dealing with mathe- 

 matics ; price and production statistics ; physical constants ; 

 chemical data ; sampling, assaying and analysis ; ore dressing ; 

 cyanidation; fuels and refractories; mechanical engineering and 

 construction; general metallurgy; and first aid. There is also a 

 good index. The book contains a vast amount of useful informa- 

 tion, and it will undoubtedly be of much value to metallurgists 

 and metallurgical chemists as well as to students preparing for 

 these professions. h. l. w. 



6. Ampere Molecular Currents. — The modern electronic form 

 of Ampere's hypothesis that magnetic substances owe their mag- 

 netic properties to the circulation of electricity in natural circuits 

 of molecular or atomic dimensions seems to involve certain diffi- 

 culties, such as the decrease in the magnetic moment of a para- 

 magnetic atom due to radiation, the existence of the so-called 

 " absolute-zero energy," etc. Hence any experimental research 

 on this subject which leads to definite results is of great interest 

 and importance. A brief outline of an investigation of this sort, 

 which has been recently carried out by A. Einstein and W. J. 

 de Haas, will now be given. 



