Chemistry and Physics. 427 



The remaining chapters save the last treat of the metals. The 

 work concludes with Chapter XXXII which in seven pages com- 

 prises a Table of Atomic Weights wherein hydrogen is the unit 

 and oxygen has the value 15-88 and gives a remarkably lucid 

 exposition of the Periodic Law. 



8. Movements of the Solar Atmosphere. — M. H. Deslandres 

 has discovered by comparison of many photographs of the solar 

 lines H and K a variation in the bright line which is found in the 

 dark space embraced by these lines. This bright line can be 

 separated into two enclosing a dark line. The bright lines cor- 

 respond to the lower layers of the chromosphere while the dark 

 line belongs to the higher layers. These bright lines often show 

 dissymmetry, sometimes one and sometimes the other becoming 

 the narrower. Spectra of the faculae do not usually show this 

 dissymmetry but it is a common condition on the remainder of 

 the surface, and is more pronounced near the equator than in the 

 neighborhood of the poles. Near spots the observed dissymme- 

 try is often in the opposite direction on opposite sides, and the 

 narrowing of the line is sometimes irregular. The phenomena 

 can be explained on the hypothesis of a continued circulation of 

 the sun's atmosphere, but it is worth noting that a less marked 

 dissymmetry has been obtained in the calcium spectrum produced 

 by the induction spark. Resemblances are pointed out between 

 these phenomena and those observed in the spectrum of Nova 

 Aurigas. — Comptes Mendus, Aug. 27; Nature, Sept. 6, 1894, p. 

 468. j. t. 



9. Luminous effects produced by electric oscillation. — H. Ebert 

 describes a luminescence lamp made of a glass globe containing 

 luminous paint. Oscillations are produced on tin foil strips 

 placed on the globe and vivid luminescence is produced. The 

 energy consumed was in the millionths of a watt, and this econ- 

 omy of the lamp was very striking. To avoid the great losses 

 due to inductive resistances a transformer with small capacity 

 and small inductance could be attached directly to the lamp.— 

 Ann. der Physik und Chemie, No. 9, 1894, pp. 144-161. J. t. 



10. The resistance of Bismuth in strong magnetic fields. — Since 

 the resistance of bismuth is increased when it is placed in a mag- 

 netic field, it has been suggested that the metal might serve to 

 measure the strength of the field. II. J. B. Hexdersost states 

 that the curve which shows the relation between the resistance 

 and the field intensity was a straight line between a field 

 intensity of 4000 C. G. S. to a field of 15,000 C. G. S. and this 

 relation holds for still more extensive fields. The resistance of a 

 bismuth wire spiral rose at the ordinary normal temperature from 

 10 ohms with a null field to 33 ohms with a field of 39,000 

 C. G. S. With lower temperatures the change is relatively 

 greater. With higher temperatures less. It may be that at a 

 certain temperature the change of resistance in the magnetic 

 field disappears. Whether this temperature coincides with the 

 melting point of bismuth can only be decided by experiment. — 



