Chemistry and Physics. 345 



of the oxygen reaction between 450 and 500°, it is calculated that 

 the speed of this reaction at 850° is 3X10 6 times as great as that 

 of the carbon dioxide and water vapor reactions. From results 

 obtained by Nernst and v. Wartenberg in regard to the dissocia- 

 tion of water vapor and carbon dioxide, it appears that oxygen at 

 atmospheric pressure and 850° has a concentration about 0*7 XlO 6 

 times as great as in water vapor and carbon dioxide at the same 

 pressure and temperature; hence it appears that there is a con- 

 nection between their dissociation and rate of action upon carbon. 

 — Zeitschr. anorgan. Chern., 1, 276. h. l. w. 



4. The Combustion of Halogen Compounds. — In determining 

 carbon and hydrogen in substances containing halogens, Charles 

 J. Robinson uses a cylinder of copper gauze tilled with lead 

 chromate in the combustion-tube. The cylinder is 6 or 7 cm. long 

 and its copper parts are oxidized before use. The lead chromate 

 is thus kept from contact with the glass. Some analyses are given 

 showing satisfactory results by the use of this device with chlorine 

 and bromine compounds, but no results are given for compounds 

 containing iodine. Strange to say, the author recommends the 

 use of the same device for nitrogen combustions, and gives a satis- 

 factory result here also. It would be expected that oxygen would 

 escape from the hot lead chromate and contaminate the nitrogen 

 jjroduced. h. l. w. 



5. Introduction to General Inorganic Chemistry, by Alex- 

 ander Smith. 8vo, pp. 780. New York, 1906 (The Century- 

 Co.). — This text-book contains many excellent features and it is a 

 very interesting work for a teacher of chemistry to read. The 

 author has wisely made the elucidation of theory the main feature 

 of the book, but an ample amount of facts is included for the 

 purpose in view. The clear and able treatment of the theories 

 by basing them upon facts is noteworthy. The book is intended 

 for the use of beginners in college courses. It is a more thorough 

 and difficult book than those generally used, but this feature may 

 be considered a favorable one. It maybe added that the subject 

 is treated from the most modern point of view, but without giv- 

 ing undue prominence to the newer theories. h. l. w. 



6. A First Course in Physics ; by Robert Andrews Milli- 

 kan and Henry Gordon Gale. Pp. v, 488, with 494 figures. 

 New York, 1906 (Ginn & Co.).— This appears to be an excel- 

 lent text-book for high schools. The aim of the authors as stated 

 in their preface has been to give " a simple and immediate presenta- 

 tion, in language which the student already understands, of the 

 hows and whys of the physical world in which he lives." This 

 idea has been consistently cariied out; the explanations are lucid 

 and free from technicalities; at the same time they are not gen- 

 'erally open to the criticism which applies to many "simple" 

 explanations, viz : that they are not true. In some cases the 

 traditional order of subjects has been abandoned and the changes 

 appear to be advantageous from the pedagogical point of* view. 



Am. Jour. Sol— Fourth Series, Vol. XXII, No. 130.— October, 1906. 

 24 



