Chemistry and Physics. 463 



tive list of references of work upon this subject. His conclusions 

 vary from those of the previous investigators. 



Fully dried glass powder absorbs a large amount of CO a . The 

 amount increases with diminishing temperature and rises with 

 increasing temperature : it is accomplished in a few hours. The 

 presence of moisture hinders this absorption. The absorption of 

 SO„ is similar to that of C0 2 : it is accomplished in a couple 

 of hours — increases with increasing pressure, diminishes with 

 increasing temperature. The following absorb in the order writ- 

 ten : C 2 H a , N 2 0, CO„,S0 2 ,NH 3 . The investigation bears upon 

 the preparation of X-ray tubes, and also upon the question of 

 the influence of the glass walls of vessels in spectrum tubes. — 

 Ann. der Physik, No. 10, 1900, pp. 328-352. J. t. 



13. Normal lines of iron. — Rowland has published a list of iron 

 lines which serve for normals in spectra comparisons. Kayser 

 finds that this list is not sufficient for certain regions of the solar 

 spectrum, and, therefore, has given a large additional number 

 between wave lengths 2300 and 4500. The author claims a 

 higher accuracy than that reached by Rowland since every wave 

 length in his table is the mean of from 6-15 measures, taken with 

 gratings of different orders. The probable error lies between 

 0-001 and 0-003.— Ann. der Physik, No. 10, 1900, pp. 195-203. 



J. T. 



14. Arc spectra of some metals in an atmosphere of hydrogen. — 

 Henry Crew finds that a hydrogen atmosphere profoundly modi- 

 fies certain arc spectra of metals, and that all the lines in the arc 

 spectra which are affected by hydrogen belong to the spark spec- 

 trum also. Moreover that the lines which belong to Kayser and 

 Runge's series are unaffected by the change from air to hydrogen. 

 — Phil. Mag., Nov., 1900, pp. 497-505. ' j. t. 



15. Recognition of the Solar Corona., independent of the total 

 eclipse. — H. Desiandres has made some observations at Meudon 

 which apparently show the possibility of observing the corona 

 under ordinary conditions by the aid of a thermopile. — Comptes 

 Eendus, Oct. 22, 1900. j. T. 



16. Loss of charge by evaporation. — Various physicists have 

 arrived at different conclusions on this subject. W. Craig 

 Henderson, working in the. Cavendish laboratory, has investi- 

 gated the subject anew and comes to the conclusion that there is 

 no appreciable loss of charge by the evaporation of a charged 

 liquid. — Phil. Mag., Nov., 1900, pp. 489-497. J. t. 



17. On the action of the coherer. — Previous investigations seem 

 to show that the action of the coherer is due to the welding action 

 of minute sparks in the powders which are employed. T. Miztjno 

 of Kyoto University has studied the behavior of a large number 

 of substances. He finds that the action of the iron powder 

 coherer is conspicuously irregular and concludes that the action 

 of the coherer can plausibly be explained on the hypothesis of 

 the welding action of minute sparks. — Phil. Mag., Nov., 1900, 

 pp. 445-459. j. t. 



