226 Scientific Intelligence. 



has undertaken to determine the quantitative relation of this oxi- 

 dation by exploding repeatedly a mixture of hydrogen and oxy- 

 gen in the same portion of air, until the volume had perceptibly 

 diminished. Knowing this volume and the composition of the 

 residual gas, he was able to ascertain that one volume of nitrogen 

 had united with two volumes of oxygen. Nitrogen dioxide, or 

 perhaps first nitrogen monoxide which is more permanent at a 

 high temperature, is therefore formed under these circumstances. 

 The quantity of the former produced is at constant pressure, 

 directly proportional to the quantity of mixed gases burned. 

 The quantity of nitrogen oxidized increases with the pressure up 

 to about 300 millimeters ; and above this appears to be constant. 

 — Ber. JBerl. Ghem. Ges., xxi, 695, November, 1888. G. f. b. 



10. Dissipation of Fog hy Electricity. — Soret places a plati- 

 num cup full of water in connection with one pole of an electri- 

 cal machine. A point above the water is connected with the 

 other pole of the machine. The water is caused to boil by means 

 of a Bunsen burner. When the machine is not excited steam 

 ascends in a regular manner, but when the water is electrified the 

 clouds whirl about until the vapor disappears. The cup is illu- 

 minated by an electric light and the experiment is made in a 

 dark room. — Arch, des Sciences, April, 188S. j. t. 



11. Magnetization of iron and other magnetic metals in a very 

 strong field. — The results of recent experiments by Professor J. 

 A. Ewing and William Low show that no considerable change 

 takes place in the value of the intensity of magnetism in wrought 

 iron when the magnetic force is varied from 201)0 to 20,000 C. G. S. 

 units. Throughout this range of force the intensity of magnetism 

 has a sensibly constant value of about 1700 C. G. S. units which 

 is to be accepted as the saturation value for wrought iron. The 

 following are the probable values of the intensity of magnetism 

 when saturation is reached in the particular metals examined : 



Wrought iron 1700 



Cast iron 1280 



Nickel (with 0*75 per cent of iron) 515 



Nickel (with 0*56 per cent of iron) 400 



Cobalt (with 1-66 per cent of iron) 1300 



Hadfield manganese steel, which is noted for its extraordinary 

 inpermeability to magnetic induction, was found to have a con- 

 stant permeability of about 1*4 throughout the range of force 

 applied to it, namely from 2000 to nearly 10,000 C. G. S. — Nature, 

 Dec. 13, 1888, p. 165. J. T. 



12. Figures produced by electric action on photographic dry 

 plates. — Mr. J. Brown illustrates his articles by interesting photo- 

 graphs obtained by passing an electrical discharge immediately 

 over or upon the surface of a sensitive dry plate. He believes 

 that the figures are not due to the brush discharge, that actual 

 disrupture discharge over or in the film is not needed to produce 

 an effect visible on development, but that figures are produced 



