450 Scientific Intelligence. 



although it had been previously supposed that a trithionate was 

 thus produced. — Berichte, xli, 300. h. l. w. 



3. Percarbonates. — Wolffenstein and Peltier have found 

 that by acting upon barium dioxide in excess with carbon diox- 

 ide in the presence of water at a low tempei-ature an unstable 

 compound, BaC0 4 is formed, 



Ba0 2 + C0 2 = BaC0 4 , 



which they regard as barium percarbonate. Very little hydrogen 

 peroxide is produced until the carbon dioxide is in excess, but 

 then it is rapidly produced, apparently according to the equation 



BaC0 4 + H 2 + C0 2 = BaCO s + H 2 2 + C0 2 . 



The same authors believe that they have shown the existence 

 of a series of sodium percarbonates, two of which are new, as 

 follows : 



Carbonate of sodium dioxide, Na 2 C0 4 . 



Bicarbonate of sodium dioxide, Na 2 C 2 6 . 



Carbonate of sodium trioxide, Na 2 CO B . 



Bicarbonate of sodium trioxide, NaHC0 4 . 



— Berichte, xli, 280. h. l. w. 



4. Practical Methods for the Iron and Steel Works Chemist, 

 by J. K. Heess, 8vo, pp. 60. Easton, Pa., 1908. (The Chemical 

 Publishing Co.) — The object of this book is to give the best 

 methods for the commercial analysis of iron and steel works 

 materials. With few exceptions only one method is given for 

 each determination, the methods chosen being those employed in 

 the laboratory of an important steel works. The directions are 

 concise and clear, all unnecessary matter being excluded, and the 

 book will be useful both to chemists of steel works and to students 

 who wish to fit themselves for this field of work. h. l. w. 



5. Laboratory Exercises in Physical Chemistry, by Frederick 

 H. Getman. Second edition. 12mo, pp. 285. New York, 1908. 

 (John Wiley & Sons.) — Only a brief notice is needed to announce 

 the appearance of a new edition of this useful book. A chapter 

 on thermostats has been inserted, and the chapters treating of 

 electromotive force, solubility and chemical dynamics have been 

 enlarged, while other minor improvements have been made in 

 the new edition. h. l. w. 



6. Quantitative Chemical Analyses, by Albert F. Gilman. 

 24mo, pp. 88. Easton, Pa., 1908. (The Chemical Publishing- 

 Co.) — This little book contains laboratory directions, questions 

 for the student, and blank forms for recording results in connec- 

 tion with a course in quantitative determinations. These exer- 

 cises for practice appear to deal exclusively with determinations 

 of constituents of pure compounds, no attention being paid to 

 the important subject of the separation of metals, etc., from 

 each other. h. l. w. 



1. Flame Spectra obtained by Electrical Means. — G. A. Hems- 

 alech and C. de Watteville lead the vapor produced by an 



