486 Scientific Intelligence. 



in treating the metal with a strong, nearly neutral solution of 

 potassium and cupric chlorides in order to dissolve the iron, and 

 then making a combustion of the filtered residue. It has been 

 known for some time that this operation involves the loss of 

 small quantities of carbon, and recently Goutal has carefully 

 studied the matter. He has found that when steels are attacked 

 by very slightly acid solutions of potassium and cupric chloride 

 at a moderate temperature and in a current of nitrogen gas, there 

 is a loss of gaseous compounds of carbon amounting to from 0*01 

 to 0-05 per cent. He states that this loss may be diminished 

 nearly one-half by making the combustion of the carbonaceous 

 residue directly after draining it with the filter pump, and with- 

 out drying it in the oven, for under these circumstances the 

 carbon dioxide formed remains entirely condensed in the residual 

 carbon. He states further that the loss of carbon may be per- 

 haps entirely avoided by boiling the copper solution resulting 

 from the operation, passing the gas which comes off with an 

 excess of oxygen through a glass tube provided with a red-hot 

 platinum wire, and collecting the resulting carbon dioxide in 

 baryta water. — ■ Comptes JRendus, cxlviii, 988. h. l. w. 



3. The Radiation of Potassium Salts. — That potassium salts 

 show a faint amount of radio-activity was first observed by 

 Campbell and Wood, and the fact has been confirmed by others. 

 E. Henriot has now made a further study of this phenomenon, 

 and finds that while others have announced that the rays from 

 potassium are very heterogeneous, his own observations lead him 

 to the conclusion that they are practically homogeneous. He 

 studied the absorption of the radiation by tin-foil of varying 

 thickness, and since the radiation-activity of potassium is of the 

 order of yowo- of tnat °^ uranium, be used 1 kg. of salt spread 

 over a surface of 1300 cm ". From the results of his experiments 

 he concludes that potassium emits /3-rays only, that there is little 

 probability that the radiation is due to an already known radio- 

 active element, and that the activity is probably caused either 

 by potassium itself, or by an unknown body which is always 

 associated with it. — Comptes JRendus, cxlviii, 910. h. l. w. 



4. A Course of Qualitative Chemical Analysis of Inorganic 

 Substances • by Olin Freeman Tower. 8vo, pp. 83. Philadel- 

 phia 1909. (P. Blakiston's Son & Co.) — The large number of 

 text-books on Qualitative Analysis which have appeared, and are 

 constantly appearing, is due to the fact that nearly every teacher 

 of the subject desires to present it to the student in a manner 

 somewhat different from that used by anyone else, either in regard 

 to the course of analysis followed, or in connection with the 

 theoretical and explanatory details. 



The book under consideration gives a well-chosen course of 

 analysis, with abundant and excellent explanatory notes, and in 

 these respects the book appears to be an unusually good one. 



The author has attempted to lead up to the facts by basing 

 them upon the theory of ions — a method of teaching which has 



