Chemistry and Physics. 



209 



gases and coal dust are particularly gootl. On account of its 

 excellent special features the book should be of interest to 

 many who are not directly connected with coal mining. 



H. L. w. 



5. Creative Chemistrij, by Edwin E. Slossox. 12mo, pp. 

 311. New York, 1920 (The Century Co.).— This book gives an 

 account of recent achievements in the chemical industries in a 

 popular and very forcible style. The subjects treated include 

 explosives, artificial fertilizers, coal-tar colors, synthetic per- 

 fumes and flavors, cellulose, synthetic plastics, rubber, sugar, 

 corn products, fats and oils, fumes for warfare, electric furnace 

 products, and metals and alloys. There are many excellent 

 illustrations, and an extensive list of references for reading is 

 appended. The book is an excellent one for the general reader, 

 and it appears to be well adapted to arouse the interest and 

 increase the knowledge of chemical students. ii. l. w. 



6. The Thermionic Vacuum Tuhe; by H. J. Van der Bijl. 

 Pp. xix, 391. New York 1920 (McGraw-Hill Book Co.).— No 

 physical discovery or development of the last decade can 

 compare in importance with the vacuum tube, which certainly 

 ranks with the telephone, and possibly with the dynamo in its 

 value to our social economy. It is the fruitage of the patient 

 labors of two generations of scientists, and the principles of its 

 operation cannot be comprehended in any engineering rule of 

 thumb. The student who seeks to master its operation will 

 have need of a thorough preparation in physics and mathema- 

 tics. 



The use of the vacuum tube was greatly stimulated by the 

 war and while much that was then discovered has possibly not 

 yet been released, the present treatise is easily the foremost 

 presentation of its theory and applications which has yet 

 appeared. Chapters I, II, III, and V treat of the nature of 

 electrons, their release from bodies and the phenomena of ioniza- 

 tion. Chapter IV details the characteristics of various tubes, 

 a technical term meaning the functional relation between the 

 variables of the tube. Chapter YI explains the use of the 

 tube as a "valve" or rectifier. Chapter YII treats tlie three 

 electrode tube or audion as amplifier. Chapter YIII is devoted 

 to the tube as generator of electric oscillations. Chapter IX 

 explains the modulation and detection of currents, and Chapter 

 X discusses the function of the tube in a variety of other appli- 

 cations. 



This exposition of the author carries especial weight because 

 he occupied for some time the position of research physicist with 

 the American Telephone and Telegraph Company and with The 

 Western Electric Company. f. e. b. 



7. OH en est La Meteorologie; by Alphonse Berget. Pp. 

 vii, 300. Paris, 1920 (Gauthier-Villars et Cie).— This is one of 

 a series of a dozen or more projected volumes {Collection des 

 Mises an Point), aiming to give a compendious presentation of 



Am. Jour. Sci.— Fifth Series, Vol. I, No. 2.— February, 1021. 

 14 



