PHYSICAL CHEMISTRY 23 



temperatures will be accompanied by ionisation. In low 

 temperature reactions, however, apart from the dissociation of 

 electrolytes in solution, the evidence for the production of ions 

 is somewhat scanty and is almost entirely confined to those 

 reactions where surfaces are being created or destroyed, as in 

 the experimental work of Haber and Just on the action of 

 water, iodine, etc., on metals, where ionisation accompanies 

 the chemical change. Pinkus and Schulthess (/. Chim. Phys., 

 1920, 18, 366 and 412, and Heh. Chim, Acta, 1921, 4, 288) 

 have continued their researches on the reactions between the 

 gases, nitric oxide, chlorine and ozone, and find, even where 

 there is no possibilit}^ of the separation of solids or liquids, that 

 positive and negative ions are developed during the chemical 

 reactions. They conclude that these electrical effects are 

 exclusively the results of the reaction processes. In the case 

 of the formation of nitrosyl chloride excess of chlorine favours 

 ionisation, and also that in the reation between ozone and nitric 

 oxide, which is accompanied by a mild explosion, intense 

 ionisation is observed. These results stand in opposition to 

 those of Trautz and Henglein {Zeit. Anorg. Chem., 1920, 110, 237), 

 who with a somewhat different experimental arrangement 

 found no trace of ionisation in several reactions — the formation 

 of nitrosyl chloride, nitrosyl bromide, hydrochloric acid, etc. 

 They suggest that the phenomena observed by Pinkus and 

 Schulthess are produced solely by frictional electricity. O. W. 

 Richardson (Phil. Trans., 1921 [A.], 222, 1-43) has examined 

 the emission of electrons which occurs when fine streams of the 

 liquid alloys NaKg and NaK are allowed to fall through 

 carbonyl chloride, chlorine, hydrogen chloride, and water 

 vapour at low pressures. The current-potential curves resemble 

 those found in thermionic emission. The energy given up to 

 the electrons by the reacting molecules is only a fraction of 

 the total heat of reaction, this energy being divided among the 

 atoms as well as among the electrons. 



Active Hydrogen and Nitrogen. — ^Venkataramaiah reports 

 {Nature, 1920, 106, 46) that active hydrogen is produced when 

 oxygen is exploded in excess of hydrogen. Wendt and Lan- 

 dauer {J.A.C.S., 1922, 44, 510) find that all ionising agents are 

 successful activators of hydrogen, with the single exception of 

 ultraviolet light, which is but slightly absorbed by hydrogen. 

 Active hydrogen is thus formed when the gas is passed over 

 a platinum wire electrically heated to 800° C. This action 

 may, however, be due to the emission of positive ions from the 

 impurities in the wire. The greatest activity was obtained in 

 a Siemens tube ozoniser immersed in liquid ammonia. Hysone, 

 as the new form of hydrogen is called, is condensed at — 180° C. 

 The spectrum of hydrogen at the temperature of liquid oxygen 



