Chemistry and Physics. , 263 



illusions ; but still he has observed that murex trunculus gives, 

 besides this reddish-violet coloring matter, also a dark blue one, 

 which results by oxidation, and not by the action of light, from a 

 colorless body. 



In spite of Friedlaender's verdict in regard to the royal purple, 

 it still seems possible that the ancients may have been able to 

 produce a really magnificent color by means of some lost method 

 of combination or manipulation. — Zeitschr. angew. Chem., xxii, 

 2321. ii. l. w. 



2. The Purification of Water Supplies by the use of Hypo- 

 chlorites. — Dr. W. P. Mason has given an account of the use of 

 bleaching powder or of sodium hypochlorite in the purification 

 of water supplies. He says that those who have been opposed 

 to this method must change their position on account of the 

 results that have been obtained in France and England, as well 

 as at the Chicago Stock Yards and with the municipal supply of 

 Jersey City. In the latter case the dose of available chlorine 

 used during the month of December, 1908, averaged approx- 

 imately 0*03 grains per gallon, and has since been materially 

 reduced. While using the above amount the daily counts of 

 bacteria per c.c. were as follows : 



Eaw Water Treated Water 



Maximum 1600 30 



Minimum.. 240 



Average 559 2 # 7 



No part of this minute dose of hypochlorite reaches the con- 

 sumer, and protection against pathogenic germs appears to be 

 assured. It is not expected that the process will take the place 

 of filtration, because it does not improve the physical appearance 

 of a water, but as an adjunct to a filter plant there can be no 

 question of its usefulness in times of emergency, and it can be 

 depended on to render a somewhat polluted water safe for 

 domestic purposes at a moderate price. — Proc. Amer. Phil. Soc, 

 xlviii, No. 191. h. l. w. 



3. Allen's Commercial Organic Analyses, edited by Henry 

 Leffmam and W. A. Davis. Fourth edition, entirely rewrit- 

 ten. Philadelphia, 1909 (P. Blakiston's Son & Co.).— The first 

 volume of a complete revision of Allen's great work will be wel- 

 comed by all commercial analysts. The revision is being under- 

 taken by specialists in the various branches of the subject, an 

 arrangement which will undoubtedly lead to a presentation of 

 the most recent and best methods. The present volume contains 

 an introduction dealing with general operations and the deter- 

 mination of physical properties of substances, and takes up the 

 subjects of alcohols, malt and malt liquors, wines and potable 

 spirits, yeasts, neutral alcoholic derivatives, sugars, starch and 

 isomers, paper and paper-making materials, and acid derivatives 

 of alcohols. The contributors to this volume are E. Frankland 

 Armstrong, Julian L. Baker, William A. Davis, G. C. Jones, 

 Henry Leffmann, Emil Schlichting and R. W. Sindall. Two of 

 these contributors and several others who will assist in the prepa- 



