Page:Popular Science Monthly Volume 4.djvu/476

460 The Nature of Ozone and Antozone.—The result of this quarter of a century of research is the present conclusion that ozone is condensed allotropic oxygen. In regard to antozone there is much difference of opinion among scientists. There are those who declare that it is a myth. The original hypothesis has recently been losing its hold on the scientific mind, and further researches are necessary to determine what it is and what it is not. The present opinion of the German philosophers is, that antozone is the peroxide of hydrogen diffused through the air.

Preparation of Ozone.—Ozone is prepared in various ways—by passing electric sparks, or electricity without sparks, through oxygen or air, by the electrolysis of acidulated water, by oxidizing phosphorus in moist air, by the action of strong sulphuric acid (three parts) on permanganate of potash (two parts), by sending water in the form of spray through air, by introducing hot glass rods into vessels filled with the vapor of ether, and by the slow oxidation of ethers and oils, etc., when exposed to light.

Properties of Ozone.—Ozone is a colorless gas, with a powerful and peculiar odor. Like oxygen, it is an oxidizing agent of great power. It changes indigo into isatin, the black sulphate of lead into the white sulphate of lead. It oxidizes antimony, manganese, arsenic, iron, zinc, tin, silver, lead, bismuth, and mercury. Many of the lower oxides it transforms into peroxides. It corrodes India-rubber and decolorizes blue litmus-paper. It acts with great rapidity on iodide of potassium, liberating the iodine. It quickly consumes ammonia, changing it into nitrate. It decomposes hydrochloric acid, liberating the chlorine. It is insoluble in acids, alkalies, alcohol, ether, the essential oils, and water. The odor of ozone is very penetrating; air containing but one millionth of it is said to be perceptible to the olfactories. The peculiar odor of sea-air is in part the result of ozone. All air, even the purest, has more or less ozone; but so accustomed do we become to it that it is only by sudden change into it that we perceive it. Visitors at the Mammoth Cave, Kentucky, report that, on emerging, the air has a peculiar and vivid odor such as they never before realized. That we can in a half-hour become so used to the foul air of a closed room that we do not perceive its odor until we leave it for a few moments and then return to it, is the experience of every one. The peculiar odor of ozone can be obtained very easily indeed by touching a metallic electrode of a galvanic battery of a number of cells against one of the plates of the batteries so as to make a connection of the current, or by touching the metallic ends of the poles for a moment with the spark thus produced.

Ozone in the Atmosphere.—Ozone, like electricity, exists normally in the atmosphere, but varies in amount in different localities at