142 GIBBS. 



solutions, water, potassium hydroxide, dilute and concentrated sulphuric acid, 

 potassium permanganate, pyrogallol, potassium iodide, and oil of turpentine, even 

 though the ozone was in some cases completely removed. 



Bredig and Pemsel " observed that the rate of the oxidation of sodium sulphite 

 is not accelerated when the air, before passing into the solution, is exposed to 

 the action of ultra-violet or Rijntgen rays, uranium or phosphorus. Ewan ^ after 

 studying the slow oxidation of phosphorus, sulphur and aceteldehyde, concludes 

 that in the process only a small portion of the o.xygen which is dissociated into 

 its atoms takes part in the oxidation. Van't Hoff ■'' in commenting upon the work 

 of Ewan says that the oxidation may be due to oxygen atoms or oxygen ions and 

 that it is not due to ozone. Eder ^'' balances the evidence by saying that in the 

 present state of our knowledge it is by no means excluded that o.xidation is 

 accelerated by contact of the oxidizable substance with the oxygen which has been 

 ionized by exposure to light and that ozone formation and ionization are ac- 

 companying phenomena. 



Prom the experiments performed with the apparatus shown in fig. 1, 

 it is to be concluded that another instance has been added to those 

 above cited, pointing to the inactivity of the oxygen ions in the process of 

 oxidation. By means of this apparatus pure, dry ozonized oxygen was 

 brought into contact with pure, dry phenol in the dark. The tube G, con- 

 taining a length of 18 centimeters of tightly packed glass wool removed the 

 gas ions ^^ produced by the brush discharge in the tube F, so that it is to be 

 presumed that oxygen in the condition of Oo and O3 (and perhaps some 

 atoms due to an equilibrium Oo «=± 20) only pass into the tube J con- 

 taining the phenol. In some experiments the glass-wool filter was 

 omitted from the chain and in others it was in place as shown in fig. 1. 

 In both cases the reaction with phenol in the liquid state, supercooled or 

 not, proceeded at once upon contact with the ozone, no ozone escaping 

 reaction with the phenol, while with phenol wliich was entirely crystalline 

 the reaction was very much diminished in speed. No variations were 

 noted between the rate or character of the reaction due to tlie presence 

 or absence of the ion filter in the apparatus chain. 



"Wlrile it is to be concluded from these experiments that ozone is a 

 form of oxygen reactive with phenol, with or without the presence of 

 the gas ions, it is not proved, from the method of experimentation, that 

 the gas ions exert no influence. 



^^Dammer, Handbuch d. anorg. Chem. (1903), 4, 122; Eder, Photochemie, 

 Halle, a/S. (1906), 87; Jahresb. d. Chem. (1899), 1, 380. 



'•'Chem.. Neivs. (1894), 70, 90. 



^Ztschr. f. phys. Chem. (1895), 16, 411. 



== Photochemie, Halle a/S. (1906), 87. 



-" With respect to the removal of the ions formed by the action of Riintgen 

 rays see Thomson and Rutherford, Phil. Mag. <C- Journ. Sci. (1896), 42, 392. 

 With respect to ions formed in other ways see Conduction of Electricity through 

 Gases, 1906, 11. On page 39 Thomson states: "From these niunbers we conclude 

 that the ions produced by Riintgen rays, by radio-active substances and by ultra- 

 violet light are identical, a conclusion which we shall find confirmed by several 

 other courses of reasoning." 



