14 
atmosphere of certain localities, or its presence therein in diminished 
amounts was associated with several violent outbreaks of Asiatic 
cholera that occurred during this period, and according to Doctor 
Moffatt ( 303 ), an English physician, the approach of an ozone period, 
during which the quantity of ozone in the atmosphere suffers a con- 
siderable increase, is followed by a corresponding increase in the 
luminosity of the glowworm and of certain phosphorescent protozoa, 
and even of phosphorus itself, when exposed to the air; and in man 
by a decided increase in the output of phosphates in the urine. Fur- 
ther, according to Doctor Moffatt, the advent of an ozone period was 
found to be marked by the approach of thunderstorms and unsettled 
weather conditions generally, and by a marked increase in the num- 
ber of cases of toothache, neuralgia, apoplexy, etc. Finally, as the 
result of a large number of observations extending over a period of 
ten years, the most exact agreement was established between the 
warnings of the admiralty cautionary telegrams, as the British 
weather forecasts were then called, and the readings of the Doctor’s 
ozonometer. The Doctor himself had evidently fallen a victim to 
ozone. 
Despite, however, the great number of faulty and imperfectly con- 
trolled observations on this remarkable substance and the erroneous 
theories arising therefrom, the fact remains that this remarkably 
active form of oxygen is produced under a great variety of conditions, 
and that it is responsible for the oxidation of many substances not 
ordinarily oxidized by atmospheric oxygen (see Wurster ( 464 )) ; and 
the fact that it is formed as a by-product in certain processes of 
autoxidation affords a simple explanation of oxygen carrying on the 
part of such substances as give rise to ozone during autoxidation. 
From the ozone theory of Schoenbein as a point of departure, our 
theoretical conceptions regarding processes of autoxidation and the 
phenomenon of oxygen-carrying have been developed mainly along 
three different lines. Briefly stated these conceptions are: (1) The 
ionization theory of Van’t Hoff; (2) the theory of Hoppe-Seyler ; and 
(3) the peroxide theory of Traube, Engler, Bach, and Manchot. 
Van’t Hoff’s theory of oxygen-activation rests upon the assump- 
tion that in slow oxidation, such as that met with in the gradual 
oxidation of phosphorus, the oxidizable substance enters into combi- 
nation, not with molecular oxygen, but with the very small amounts 
of atomic (ionic) oxygen which are constantly being produced from 
molecular oxygen in the sense of the equilibrium 0 a =20, and that in 
a gaseous system such as that furnished by acetic aldehyde and 
gaseous oxygen, the velocity of the reaction should be exactly pro- 
portional to the square root of the oxygen pressure. 
The idea that molecular oxygen dissociates as the result of electri- 
fication and under the influence of heat and chemical action, is by , 
