Chemistry and Physics. T3 



3-383 X 10- 7 and 3-415 X 10~ 7 by different methods. S. C. Lind 

 and L. D. Roberts have now made a very carefnl determination 

 of the ratio, which seems to be particularly reliable on account 

 of the many precautions used and from the fact that their stand- 

 ard radium chloride was the pure salt and gave the same amount 

 of radium by calculation as by comparison by the y-ray method 

 with the International Standard. The result, the average of 18 

 determinations, is 3-40 X 10~ 7 ± 0-03. It agrees with the aver- 

 age of the results of Becker and Jannasch and also with Bolt- 

 wood's result before it was modified by Rutherford. — Jour. 

 Amer. Chem. Soc, 42, 1170. h. l. w. 



3. Treatise on General and Industrial Inorganic Chemistry; 

 by Ettore Molinajri. Large 8vo, pp. 876. Philadelphia, 1920 

 (P. Blakiston's Son & Co.). — This is the second English edition, 

 translated from the fourth revised and amplified Italian issue by 

 Thomas H. Pope of England. The book is a very noteworthy 

 one in being a combination of a good treatise on inorganic chem- 

 ical facts and theories with a very elaborate presentation of the 

 industrial side of the subject. There is another volume dealing 

 in a similar way with organic chemistry. There has been of late 

 years an increasing tendency to introduce some examples of 

 industrial applications into text-books of general chemistry, and 

 we have here in the volume under consideration a very impres- 

 sive extension of this idea with the hope of reforming and 

 improving the usual method of teaching chemistry. It . is the 

 view of the author that general chemistry can no longer be a 

 simple and arid exposition of fundamental laws and of the 

 properties of innumerable known substances, but should possess 

 a soul which brings it into contact with the vital activities around 

 which it clings. It appears that this ground is well taken, since 

 it is desirable to arouse interest and enthusiasm and to develop 

 practical knowledge and ability in our students. 



The book gives excellent descriptions of the important inor- 

 ganic chemical industries, including those of metallurgy. It 

 gives much interesting historical information in regard to these 

 industries, it is provided with 328 illustrations and two phototype 

 plates, it gives also a great many useful statistics of production 

 and prices, and without doubt it should receive the careful atten- 

 tion of our teachers of general chemistry. Coarser and smaller 

 type are used in printing the book, so that the former may be 

 assigned to the student for particular study without involving 

 an undue amount of text, while the remaining, much larger part 

 would undoubtedly be read to a considerable extent by students 

 for the sake of its interesting and important information. 



Morover, the matter relating to industrial processes furnishes 

 a very satisfactory text for more advanced students. 



h. l. w. 



4. Laboratory Manual of Elementary Colloid Chemistry; by 

 Emil Hatschek. 12mo, pp. 135. Philadelphia, 1920 (P. 



