160 Proceedings of Indiana Academy of Science 
increase in the surface." A platinum wire that had been used as an 
electrode for corona work was found to have suffered similarly. And 
with the increase in the surface there was a notable increase in a “lag 
40 
O2 
ISS. PERIODS LUNUTES 
FIG. I. FIG. II. 
Fig. I. The “lag effect’? due to a platinum wire. A continuous discharge was 
passed through air flowing at the rate of 190 ce. per min. so that the air in the tube 
would be renewed in 18 min. The continuous line indicates the actual results for suc- 
cessive five min. periods. The break in this curve occurs with the elimination of the 
lag effect. The dotted curve shows the normal course of ozone production without any 
complicating lag effect. 
Fig. II. Evidence of an “ionization pressure’. The discharge was passed through 
enclosed air and the pressure was followed by a manometer containing a pure paraffin 
oil. At A and C the current was turned on and at B and D it was turned off. The 
jumps are too great to be caused ‘by the rise in temperature. 
effect”. In Fig. 1 the continuous line follows the actual results ob- 
tained in a typical run. Air was passed through the apparatus con- 
tinuously at a rate of 190 cc. per minute, so that the air in the tube 
was replaced every 18 minutes. After five minutes of discharge the 
outcoming air was analyzed for ozone during the second five-minute 
period in one analysis apparatus and during the third five-minute period 
in another apparatus. Average yields of ozone per minute during each 
five-minute period are given. The air that comes out of the tube at 
first contains less ozone than after it has had a chance to come in 
contact with the discharge during its whole passage through the tube. 
Because of the very marked electric wind the effect of any slower rate 
of flow along the walls than in the middle was largely eliminated. 
6 Jbil, p. 2593. A considerable amount of material is accumulating in this laboratory 
as to the properties and nature of this lag. It will be assembled in a separate publica- 
tion. For the illustration of the charge on the surface of platinum see Rideal and 
Taylor, Catalysis in Theory and Practice, Longmans Green & Co., 1919. 
