17 
On the other hand, the active agent produced during the slow oxida- 
tion of phosphorus diffuses with considerable velocity, even against a 
current of air. Potassium and sodium burning in contact with water 
also exert an influence on the steam jet through great distances. As 
has been observed in the case of phosphorus, the resulting cloud, which 
consists of finely divided potassium or sodium oxide or hydroxide, is 
of itself inactive. It is also known that potassium and sodium glow 
on their freshly cut surfaces as the result of autoxidation. Plence all 
these phenomena are analogous to those observed in the burning of 
phosphorus. 
According to these observers, it can readily be understood that in 
all oxidations occurring in atmospheric air there are produced so 
many substances that it is often difficult or impossible to obtain 
experimental proof by the exclusion of all other causes, that the action 
on the steam jet is only brought about by ions, especially those of 
active oxygen. Of the three substances, however, which are always 
produced during combustions in air, namely ozone, nitrous acid, and 
hydrogen peroxide, none were found to have any action on the steam 
jet. 
In this connection it is of interest to note that Meissner ( 297 ) as early 
as 1863 had observed that under the excitation of oxygen by elec- 
trical induction there is produced, besides ozone, still another sub- 
stance, which exerts a highly remarkable action on water vapor. Fur- 
ther investigations led him to believe that this substance was Schoen- 
bein’s antozone. 
According to Yon Helmholtz and Richarz ( 208 ),in all such oxidation 
processes as effect a condensation of aqueous vapor in the steam jet, 
the oxygen is dissociated into single atoms (ions), Ot and 01, or into 
groups of atoms such as — O — 0 — . In terms of the electro-chemical 
theory both of these kinds of particles have free valences and are car- 
riers of an excess of positive or negative electricity, and hence serve to 
conduct the current through the gas during electrification, or, as 
explained by Thomson (see p. 16), they cause a condensation of aque- 
ous vapor when they come in contact with the steam jet. According 
to Von Helmholtz and Richarz ( 20S ), chemists have ascribed to active 
oxygen only a momentary existence; on the other hand, Clausius ( 121 ), 
on purely physical grounds, postulated the existence of dissociated 
atoms of oxygen at least as a transitional form enduring certainly for a 
short time, and if we judge from their conduct toward steam these par- 
ticles of active oxygen exist for a sensible interval. By means of te- 
tramethyl-p-phenylene-diamin, which is colored blue by contact with 
monatomic oxygen (antozone), Wurster ( 4R4 ) was able to obtain evi- 
dence of the existence of the dissociation products of oxygen in the 
vicinity of gas flames. Thus Wurster s reagent is instantly colored 
intensely blue in the Bunsen burner flame; more slowly, but still visi- 
1167C— Bull. 59— 10 : 2 
