Meissner’s Researches upon Electrized Oxygen. 219 
again enters the tube, the yellow crust a to be again 
formed as often as the electrized oxygen acon r it. Since 
remains. In the one case partial absorption of both is equal, 
in the other unequal. One of these classes requires for its 
oxydation more ozone than antozone, the other requires them 
in equal proportions ; —_ there is a third class requiring 
more sige than oz 
important prac aoundl application is _— of these facts to 
the Pa ao of potassium iodid as an absorbing solution. 
A neutral solution of this wath becomes alkaline a 
subjected to the action of ozone, and contains free 
te, which, acting as above, diminishes the antozone. By 
So arranging the apparatus that acid or alkali can be added at 
pleasure to the iodid solution, the mist is seen to be diminished 
on making it atk line and increased when it is made acid. 
The neutral solution of potassium iodid is not therefore a suita- 
ble de-ozonizing agent, if it is desirable sl it to pro- 
served was obtained by ammonium sulphid as de-ozonizer, 
this compound absorbing mor ozone and less antozone than any 
other substance tried. hen ammonium hydrate is submitted 
