Chemistry and Physics. 451 



arc lamp — provided with various forms of carbon — into a Bunsen 

 flame. If iron vapor is led into this flame, its spectrum is seen 

 together with a strong continuous background : the latter disap- 

 pears if the vapor is filtered through glass wool before reaching 

 the flame. — Comptes Rendus, cxlv, Dec. 16, 1907, pp. 1266-1268. 



J. T. 



8. 'Electric Furnace Reactions under High Pressure. — R. S. 

 Huttojst and J. E. Petavel describe their experiments and give 

 preliminary results. Electromotive forces of 25,000 volts and 

 pressures of 200 atmospheres were employed. A concentrated 

 and compressed atmosphere of CO has little effect upon the 

 formation of calcium carbide. Under high pressures the produc- 

 tion of carborundum becomes very difficult, which confirms the 

 view that it is formed by the interaction of silica vapor with 

 highly heated carbon. — Roy. iSoc. Phil. Trans., Ser. A 207, Jan. 

 17, 1908, pp. 421-462. J. T. 



9. The Positive Column in Oxygen. — Rev. P. J. Kieby has inves- 

 tigated the electric force in the positive column when a steady 

 electric charge passes through oxygen at low pressures between two 

 plane-parallel electrodes placed in a straight glass tube. He finds 

 that the force presents exceptional features in the case of oxygen — 

 being much smaller than in other common gases — and instead of 

 diminishing continually with the pressure, reaches a minimum of 

 about 2*0 mm pressure, and there is a sharp discontinuity at a pres- 

 sure of •8 mm . The method employed did not involve the use of 

 an exploring wire. The author attributes the discontinuity to the 

 presence of ozone. — Phil. Mag., April, 1908, pp. 559-568. 



J. T. 



10. Quadrant Electrometers. — H. Schulze discusses the error 

 or disturbances which arise from contact difference of potential 

 in the use of very sensitive electrometers, and suggests precau- 

 tions in their use. — Zeitschrift Instrumentenkunde, March, 1908, 

 pp. 61-69. j. t. 



11. The Reception of Electric Waves in Wireless Telegraphy. — 

 In a discussion upon the amount of energy received by the 

 antennae employed in wireless telegraphy, Reinhold-Rudenberg 

 confirms the result of R. A. Fessenden that long waves are more 

 efficient than short waves for overcoming great distances. He 

 proves that in general the amount of energy received increases 

 with the square of the wave length, and shows how very small 

 the amount of energy is which is received, and how fallacious is 

 the hope that any large or rational amount can ever be transmit- 

 ted by electric waves through the ether. — Ann. der Physih, No. 

 3, 1908, pp. 446-466. J. T. 



12. Velocity of Sound. — By means of resonators, M. Thiesen 

 has determined this velocity in air at 0° C. and finds it 

 3-3192 Xl0 10 ±5 cm /sec— zto. der Physih, No. 3, 1908, pp. 506- 

 520. j. t. ' 



13. Diffraction of X rays. — Hayn and Wind claimed to have 

 shown the diffraction of these rays and their results are quoted 

 in various treatises ; notably in Prof. J. J. Thomson's work on 



