Chemistry and Physics. 189 



4. Volumetric Determination of Selenious Acid. — L. Marino 

 has devised a method for this purpose which he prefers to those 

 previously in use. The solution of the selenious acid is made 

 slightly alkaline with sodium hydroxide solution, then a specially 

 prepared alkaline permanganate solution is added gradually, 

 until after heating to boiling a strong violet color is permanent 

 for 4 or 5 minutes. After cooling somewhat the liquid is acidi- 

 fied with dilute sulphuric acid, and an oxalic solution is run 

 in until all the manganese dioxide has dissolved. Then, finally, 

 the excess of oxalic acid is titrated with the permanganate 

 solution. The test-analyses given show very satisfactory results. 

 A special method is given for the removal of nitrates in order 

 that this method may be applied. — Zeitschr. Anorgan. Chem., 

 lxv, 32. h. l. w. 



5. A Contract for Radium. — It is stated on the authority of 

 the London Times that a contract has recently been entered into 

 between the British Metalliferous Mines (Limited) and Lord 

 Iveagh and Sir Ernest Cassel for the supply of 7-J grams of pure 

 radium bromide at the rate of four pounds per milligram (total 

 about $150,000). The source is pitchblende from the company's 

 mine in Cornwall. This radium bromide is to be presented by 

 Lord Iveagh and Sir Ernest Cassel to the Radium Institute, 

 which will be under the direction of Sir Frederick Treves, for 

 use in the treatment of cancer. — Chem. JVeivs, xci, 303. h. l. w 



6. Absolute Measurement of High Pressure ivith the Amagat 

 Manometer. — Peter Paul Koch and Ernst Wagner have de- 

 scribed in a previous paper a method of measuring accurately 

 high pressures which gave very satisfactory results ; but in order 

 to reach a higher degree of exactness they concluded to measure 

 the pressures directly by a height of mercury. The tower of the 

 Laboratory in Munich afforded a height of 25 m , and they describe 

 the arrangement of steel tubes by means of which they contained 

 the mercury. A comparison is given of the results of the Ama- 

 gat manometer, with the results obtained by direct measures, 

 obtained from the height of the mercury column. A constant of 

 correction is given. — Ann. der Physik, 1910, No. 1, pp. 31-50. 



J. T. 



7. A Relation Between Absorption and Phosphorescence. — 

 The observations of M. G. Lecoq de Boisfaudran and M. G. 

 Urban show that the best known phosphorescent bodies result 

 from a phosphor 'ogene in a solvent or diluent. M. L. Bruning- 

 haus points out a very simple relation between absorption and 

 phosphorescence. The light emanating from the phosphoroge?ie 

 molecules situated in the depths of the medium suffer absorption 

 by the superficial layers, and the radiations observed at the sur- 

 face are only those for which the phosphorogene is relatively 

 transparent.— Comptes Pendus, Dec. 13, 1909, pp. 1124-1129. 



J. T. 



8. Mass of Moving Electrons. — The new theories of electrons 

 are concerned with hypotheses of change of mass with velocity. 



Am. Jour. Sci. — Fourth Series, Vol. XXIX, No. 170.— February, 1910. 

 13 



