12 
4. The apparent occurrence of antozone in nature in certain varie- 
ties of fluorspar, and its apparent formation (or the actual formation 
of hydrogen peroxide, an antozonide) by the action of an acid on an 
antozonide hke barium peroxide. 
While the differences existing between the so-called ozonides and 
antozonides and also their mutual decomposition, can be explained 
upon grounds 0 other than those involving the idea of oppositely elec- 
trified oxygen atoms. Schoenbein's theories respecting the nature of 
this interesting group of substances were more or less in harmony 
with the dualistic theory of Berzelius and with the fact that the mole- 
cule of oxygen consists of two atoms. Their principal interest in this 
connection is that erroneous as they were in some particulars, they 
afforded a satisfactory explanation of oxygen activation. A few 
examples will serve to make tins clear: When a solution of indigo 
blue is exposed to oxygen or atmospheric air it suffers no change. 
On the other hand, as is well known, phosphorus is readily oxidized 
under these conditions. And now, what is more remarkable, if 
indigo be brought in contact with slowly oxidizing phosphorus, not 
only does the phosphorus continue to be oxidized but under these 
new conditions the indigo is oxidized as well. In other words, oxid- 
izing phosphorus has the power to excite or induce the oxidation of 
a substance which alone is incapable of undergoing oxidation by 
simple contact with oxygen or atmospheric air. As shown by Schoen- 
bein, however, when phosphorus is slowly oxidized in the air ozone 
is produced and it is the latter substance which oxidizes the indigo. 
When a solution of potassium iodide and starch or a suspension of 
guaiacum resin in water is shaken with air. no change of color occurs. 
If, however, as shown by Schoenbein ( 380 ). a drop or two of oil of 
bitter almonds be added to these solutions and the solutions after- 
wards shaken with air, each of them becomes blue in color, due in 
the first case to the oxidation of the potassium iodide with the setting 
free of iodine and the formation of the blue iodide of starch, and in 
the second case to the oxidation of the guaiacum with the production 
of guaiacum blue. According to Schoenbein. the oil of bitter almonds 
ozonized the air and the resulting ozone oxidized these substances 
which are not oxidizable bv oxvgen in its ordinary form. 
He also made the interesting observation that certain of the higher 
fungi, as well as other plants, contain substances which apparently 
have the power of ozonizing the air to a remarkable degree, thereby 
accomphshing the oxidation of substances not oxidizable by ordinary 
a Mendelejetf 299 divides the peroxides into two classes. 1. superoxides, in which 
the oxygen atoms are directly united to one another as well as to the oxidized element, 
and 2. polyoxides, in which the oxygen atoms are not directly united with one another. 
The superoxides yield hydrogen peroxide when dissolved in acids; the polyoxides 
do not. Similar dews are held by Traube and by Richarz ( 349 ). 
