34 
POPULAR SCIENCE REVIEW. 
experiments have been made in different portions of the world 
to allow of a correct average being determined : we must take 
one part in ten thousand as an approximative, not an actual 
value. 
The natural process leading to the production of Ozone in. 
the atmospheric sea is not as yet understood. At first, 
electrical storms were conceived to be the means of produc- 
tion ; then Professor Dove advanced the idea that the Ozone 
is generated in the upper equatorial currents of air, and is by 
these diffused over the planetary surface with the north and 
south winds ; and again Dr. Moffatt, whose labours in this de- 
partment of science cannot be over-estimated, considers that 
Ozone is connected with the phenomenon of phosphorescence, 
and that, in short, it is produced in nature at large as we have 
seen it produced in the laboratory as a result of phosphorous 
oxidation. Of all these theories, that of Dr. Moffatt is the most 
simple, and is best supported by observation. 
When we know the two facts that Ozone purifies decom- 
posing organic substances, by breaking up the offensive 
deleterious products of decomposition, and that it exists 
naturally in the air we breathe, we might infer that it fulfilled 
some useful purpose in the universe, without speculating 
rashly. But we have no occasion to speculate at all, for we find 
as a positive fact, sustained by the most perfect evidence, that 
Ozone is usefully employed, and that in truth it is the great 
purifier of the impure air of city and town. It is now proved 
that the Ozone in air, after it is diffused through town and 
city, is no longer to be detected there by the most delicate 
tests for its presence. Hence it is said to be lost in towns ; in 
other words, it is used up in the process of destroying those 
exhaled substances which pass from the bodies of men and 
animals, a-nd which escape from the organic debris that neces- 
sarily accumulate in and about every human habitation. 
Were the formation of Ozone to cease in nature, I doubt if 
life could exist on this globe, according to the present con- 
stitution of terrestrial laws. 
Turn we now to the effects produced by Ozone on living 
animals. The light rests steadily here on some facts of great 
interest. By means of Siemenses apparatus, I have been able 
to determine with accuracy the action of this remarkable body 
in its concentrate form on healthy living organisms. 
When air containing an excess of Ozone is breathed for some 
minutes, it produces, first, a sense of irritation of the nose and 
throat, with sneezing, and soon a dull heavy pain in the head, 
and headache more or less severe. After a time there is 
watery discharge from the nostrils, and free secretion from the 
