Meissner’s Researches upon Hlectrized Oxygen. 221 
prevent the entrance of moisture into the electrizing tube, 
lessens the amount of ozone and antozone obtained. 
IL. 
Section II treats of the “ Quantitative estimation of Ozone, 
and the contraction of volume on electrizing oxygen.” The 
apparatus employed is similar to that above descri ed, the elec- 
trizing tube being calorie to enclose a thermometer, and hay- 
ing a delicate mercury-manometer sapodest ad to it. A bulb- ae 
Lorene In making an observation, the apparatus is filled 
pure oxygen, the manometer, barometer, and thermometer 
“4 the ox ygen ele ctrized, time allowed for the 
quantity of active oxygen determined: Ist, by the increase in 
weight of the bulb apparatus, and 2d, by poration with sodium 
thio- -sulphite or occasionally, sodium sulphite. The free iodine 
is first determined, and t en the solution is acidulated with 
hydrochloric acid; the hydriodic acid thus set free reacts 
with the iodic acid to set free more iodine, which is then 
‘87 
given in the tbl, this proportion is not reached, but varies 
from 1:149 to 1:18. This variation, observ ed by other 
experimenters, was Peep ioral B. “Tt was found not to be due 
to the action of the unozonized oxygen, nor to an 
iodine in the care nor to imperfections in the titrition 
itself; nor did i hen the iodine was completely 
passing, ee the fact that ozone is — y a modification 
ydrogen peroxyd 
is produced in it; and that the iethed of experimenting here 
employed is free from. errors. He believes too, that the varia- 
tions observed when the potassium iodid is incompletely oxyd- 
ized, may be due to the production of some intermediate oxyd 
of iodine ; and thence, regards the method by weight as less. 
liable to error in estimating the amount of ozone, than the 
