440 KEPORT— 1893. 



III. Studies on the Formation of Ozone from Oxygen.^ 

 By W. A. Shenstone and Martin Priest. 



The introduction of improved methods of working with ozone have 

 enabled the authors of this paper to study the influence of various con- 

 ditions on the converting of oxygen into ozone with increased exactness 

 and facility. 



The results obtained show that — 



1. Under constant conditions it is possible to obtain concordant results 

 in converting oxygen into ozone by the silent discharge. 



2. That the maximum yield of ozone is nearly independent of the 

 difierence of potential employed to produce the discharge (the range ot 

 potential difference employed was from 33 to 69 C.G.S. units), provided 

 that the path of the discharge be not too short. 



3. That if the path of the discharge be very short, then the maximum 

 yield of ozone has an inverse relation to the difference of potential 

 employed.^ 



4. The rapidity with which the discharge converts oxygen into ozone 

 is greater when great potential differences are employed than for smaller 

 differences. 



5. That the maximum yield of ozone is less when the number of dis- 

 charges is very great in unit time than when it is smaller.^ But the yield 

 is not affected by moderate variations of rapidity of the discharge. 



6. The greatest yield of ozone was obtained by using an ozone gene- 

 rator made of the thinnest possible glass, and with closely fitting tubes. 

 In one case 17'15 per cent, of ozone was obtained at 0°. 



7. Under equal conditions less ozone was produced by the discharge 

 obtained by means of a Wimshurst's machine than when a large induc- 

 tion coil was employed. 



It has been suggested that this last phenomenon may be due to a 

 difference in the quantity of electricity acting in the two cases, but the 

 authors point out that under the conditions of their experiments ■* the 

 ' quantity ' of the discharge inside the ozone generator depends on the 

 difference of potential of the inducing charge, and that as the ozonising 

 effect of the discharge is, under suitable conditions (see 2 and 3 above), 

 independent of the potential difference of the inducing charge, it would 

 seem that this suggestion does not afford a clue to the cause of the phe- 

 nomenon. Moreover, it was found in the experiments made with the 

 plate machine that when the quantity of the inducing charge was raised 

 or reduced, by means of condensers, the yield of ozone remained un- 

 affected. 



Although a good deal of progress has now been made, much of the 

 work undertaken remains to be done. As, however, no further grants are 

 likely to be asked for, and as it is probable that in the future the work 

 will be mainly in the hands of one member of the Committee, the 

 Committee now recommend that they be not reappointed. 



' Jo7irn. CJiem. Soc, 1893. 



^ This is attributed to the difficulty of maintaining a sufficiently regular tempera- 

 ture of the gas under these circumstances. 



' This is also probably due to imperfect refrigerating. 

 * Ozonisers of Brodie's type were employed. 



