80 Scientific Intelligence. 



7. Annual Reports of the Progress of Chemistry for 1904.. 

 8vo, pp. 280. London, 1905, Gurney & Jackson (D. Van Nos- 

 trand Co., N. Y.). — We have here the first annual volume of a 

 condensed review of the progress of chemistry, prepared under 

 the direction of the London Chemical Society. The branches 

 treated are General and Physical Chemistry, Inorganic Chem- 

 istry, Organic Chemistry — Aliphatic Division, Organic Chem- 

 istry — Aromatic and other Cyclic Divisions, Stereochemistry, 

 Analytical Chemistry, Physiological Chemistry, Agricultural 

 Chemistry and Vegetable Physiology, Mineralogical Chemistry, 

 Radioactivity. Each section has been prepared and is signed by 

 a specialist in the line of work under discussion. The work is to 

 be heartily welcomed, since it is the only thing of the kind in 

 the English language, and it will be useful to many who are 

 interested in the progress of the various branches of the science. 



h. l. w. 



8. A New Kind of X-ray. — W. Seitz believes that he has 

 proved the existence of rays analogous to the X-rays which can 

 be produced by as low voltages as 600 volts; the tube or bulbs 

 he employed were from 5 to 7 centimetres in diameter, but he 

 does not state the distance between the electrodes. Photo- 

 graphic plates were exposed to the rays in a vessel which was 

 deprived of air ; for air, as in the case of ultra-violet rays of 

 light, greatly absorbs the new rays. A marked effect was 

 observed on certain forms of bacilli. They were destroyed on 

 the surface of the preparation containing them ; since the 

 preparations absorb the rays, the medical uses of the rays 

 seem to be limited. — Physikalische Zeitschrift, Nov. 9, 1 905, 

 No. 20S, p. 756. j. t. 



9. Magnetizing by Rapidly Oscillating Currents. — The mag- 

 netic detector discovered by Rutherfurd and utilized in wireless 

 telegraphy by Marconi has been investigated by E. Madelung, 

 with reference to changes in the bytersesis curve produced by the 

 rapidly oscillating currents of condenser discharges. By an 

 ingenious disposition of the magnetic detector its rapidly chang- 

 ing magnetism caused a movement of the fluorescent spot in a 

 Braun tube giving the ordinary magnetizing curve with the change 

 due to the oscillating currents superposed upon it. The author calls 

 the magnetizing curve produced by steady currents the static 

 magnetizing curve, and the magnetizing curve due to the rapidly 

 changing magnetism, the dynamic curve. Curious loops are pro- 

 duced by the oscillating currents which fall outside the area of 

 the static magnetizing curve which are due to eddy currents. 

 These loops cause a discontinuity which accounts for the detector 

 action of the bundle of fine steel wire constituting the core of the 

 instrument. — Ann. der PhysiJc, No. 10, 1905, pp. 861, 890. J. t. 



10. Influence of the Earth in Wireless Telegraphy. — J. S. Sachs 

 finds that with short waves it is desirable to insulate the appara- 

 tus as high as possible above the earth and to dispense with the 

 earth connection of the apparatus. If the apparatus is in the 



