, 1873-11-19
ROYAL INSTITUTION LECTURES.
(COntinued.l
HISTORY OF OZONE.

O8ON0s
Professor OdIing, F. R. s., gave the con-
Guiding Friday evening discourse on the
9TH inst. He began by observing that
while the action Of oxygen in the free state,
whether by itself or as it exists in the at
mosphere in a state Of dilution with nitro
gen, is very gradual, the similar action of
another elementary gas (chlorine), and of
oxygen itself when existing in a state OF
a peroxide, as in peroxide of nitrogen
is decided and immediate. Under Ger
tain conditions, however, oxygen or air,
without the addition Of any other kind of
matter to it, is found to acquire the ener-
getlc properties possessed by air of oxygen
to which a small proportion of chlorine or
peroxide OF nitrogen has been added.
These properties are mainly a characteristic
penetrating smell and a power of attacking
metals (as mercury, of bleaching and cor
rolling vegetable fabrics, and of liberating
iodine from iodide Of potassium. Unlike,
however, the similar properties of air or
oxygen contaminated with chlorine or
peroxide OF nitrogen, these properties Of
so-calIed ozOnised air are not affected by
passing the air thorough o solution of car
donated alkali, but are destroyed by passing
it through u tube heated from $50 deg. to
800 deg centigrade. The means for inn
parting to or oxygen this active character
are mainly these:-First, by submittiny it
to electrisatiOn. This method of oz)nifica-
ton has undergone a great Improvement by
the substitution of an iniuctive electric ac-
ton effected in a form Of instrument de-
vised by Mr.. Slemens) for the simple cleo
tic discharge. Secondly, by procuring oxy-
gen as a produce Of the eIectroIysis of oxi-
dulated water, decomposed by Groves
battery, atfording a current of much iuten-
sity; by passing moist air over phosphorus,
SO as To effect its gradual oxidation. Other
methods Observation-Disclosures but all ozod-
Used air or gas that has been made the sub
tct OF experiment has been obtained in one
or other OF these ways. The first step in
the history of the subject was made by
Sch0nbeln, in IS40 5, WHO demonstrated
that the energetic properties acquired by
air or Oxygen, when submitted TO the tore
going modes of treatment, are really due to
the formation in the air, or oxygen, OF u new
0dOrus substance, to which he gave the
name of yzone (frOm the Greek Ozein, to
have a smelly. The next step was the de-
monstratiou effected mainly by Marignac,
in 1919 that ozqne is constituted either of
oxygen alone or of oxygen with the addit-
ton OF the elements of water. This was
followed by the demonstration, contributed
by many observers, that the matter ofozene
is Identical with the matter of oxygen
ozone being produced Independently Of
the presence, and being decomposed with
out the production, of even a trace of moist
ure. The next, aud very important step
was the establishment by Andrews and
TAFT, i'll 1860, that ozone is merely a con-
densed form of oxygen. This conclusion
was afterwards confirmed by Tyndall, and
also by other observers. The last step in
the history of ozone is the recent demon
s%tration by Sir B. Brodie, in a series of
very exact aud laboriOus experiments, that
ozone is one and a half times denser than
ordinary oxygen; or that the weight of
the matter of oxygen contained 10 any
volume of ozone is one and q half times
greater than the weight of the matter of
oxygen contained in the same volume of
ordinary oxygen. The probability Of this
being the relationship between oxygen
and ozone had been pointed out by the
lecturer some ten years ago as a deduction
from the experiments Of Andrews and
TAFT, and some experiments were afterwards
made by Soret, not, indeed, giving very
exact results. con6rmatOry of DR., OdliDg's