348 iScieutiJio Intelligence. 



manner of presonting tlie subject. 'Vhv book appears to have 

 many excelK'nt features, and it. presents a rather extensive course. 

 The illustrations and diagrams an; generally good, the experi- 

 ments are numerous and instructive, and the theory for the most 

 ])art is clearly presented. However, the author persists in giv- 

 ing incorrect formulas for the common elementary gases, II, (), N, 

 for example, instead of H.^, O.^, N„, and in this way his "original 

 device of diagrams" for explaining Avogadro's law gives an 

 entirely false im|tression of the subject, while the simple matter 

 of gaseous combination is at the same time made exceedingly 

 difficult, if not impossible to understand. A good many mis- 

 prints or misstatements have been noticed. A serious mistake is 

 made in describing an electrolytic apparatus for manufacturing 

 caustic soda, where it is stated that the sodium chloride \fi fused 

 in contact with a layer of mercury, an imj^ossible condition of 

 things on account of the temperatures at which mercury b'oils 

 and salt fuses. h. l. w. 



4. A Text-Book of Organic Chemistry ; by William A. 

 NoYES. 12mo, pp. 537. New York, 1910 (Henry Holt & Co.). — 

 This is a revised, second edition, of tlie work which ai^peared 

 about seven years ago. It is so well known to the chemical 

 public that it requires no special comment, except that a few 

 changes and additions have been made, most of which were pre- 

 pared for the German edition, and that the short final chapter on 

 compounds of interest in physiology and pathology has been 

 re-written. h. l. w. 



5. AUen^s Commercial Organic Analysis, Fourth edition ; 

 edited by W. A. Davis and Samuel S. Sadtlk.r. Vol. HI, 8vo, 

 pp. 635. Philadelphia, 1910 (P. Blakiston's Son & Co.).— This 

 important work, which is being entirely re-written in tht^ prestmt 

 edition, will consist of eight volumes when complete. The third 

 volume, under consideration, treats of the hydrocarbons, includ- 

 ing oletines, acetylenes and tars, bitumens, including the various 

 petroleum products and the coal-tar hydrocarbons, naphthaline 

 and its derivatives, anthracene and its associates, phenols, aro- 

 matic acids, gallic acid and its allies, phthalic acid and phtha- 

 leins, and modern explosives. h. l. av. 



6. Analytical Cheinlstry. Volume IT, Quantitative Analysis,' 

 by F. P. Treadwell. Ti-anslated by William T. Hall. 8vo, 

 pp. 785. New York, 1910 (John Wiley & Sons).— This excellent 

 text-book, which now appears in the second American edition, has 

 been compared with the fourth German edition. The total issue 

 of the book, six thousand copies, indicates that it is very exten- 

 sively used in the United States. h. l. w. 



7. Ozone and Ultra- Violet Light.— 1% has been supposed that 

 ozone is produced in the upper regions of the atmosphere by 

 means of sunlight, and the ionizing eflf'ect of this light— mainly 

 coming from short wave lengths — has been supposed to influence 

 the transmission of electrical waves. E. v. Bahr concludes that 

 since the ozonizing rays are strongly absorbed by air the ozoniz- 



