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1851.] OF THE ROYAL INSTITUTION. 95 
in almost every case of electrical discharge in the air; or when 
water is electrolyzed, as in the case of a dilute solution of sulphuric 
acid or sulphate of zinc; or when phosphorus acts at common 
temperatures on a moist portion of the atmosphere. For the latter 
case take a piece of clean phosphorus about half an inch long which 
has been recently scraped; put it into a clean two-quart bottle, at a 
temperature of about 60° F, with as much water as will half cover 
the phosphorus; close the mouth slightly so that if inflammation 
take place no harm may happen; and leave it. The formation of 
Ozone will quickly occur, being indicated by the luminous condition 
of the phosphorus, and the ascent of a fountain-like column of smoke 
from it. In less than a minute the test will show Ozone in the 
air of the bottle, in five or six hours it will be comparatively 
abundant; and then the phosphorus being removed and the acids 
formed at the time washed out, the bottle may be closed and made 
use of when required for experiments. 
The test for Ozone is as follows: 1 part of pure iodide of 
potassium, 10 parts of starch, and 200 parts of water are to be 
boiled together for a few moments. A little of this preparation placed 
on writing paper with a brush being introduced into the Ozone 
atmosphere is rendered instantly blue from the evolution of iodine :— 
or if bibulous paper be dipped into this solution, and then dried, it 
forms Schénbein’s Ozonometric test: for a slip being introduced dry 
into an atmosphere supposed to contain Ozone, after remaining 
there a longer or shorter time, on being removed and then moistened, 
instantly becomes more or less deeply blue if Ozone be present. 
Ozone when obtained by the three very different processes 
described is identical in every respect : its properties are as follow: 
1. It is a gaseous body of a very peculiar odour : when concentrated 
the odour approaches to that of chlorine ; when diluted it cannot be 
distinguished from what is called the electric smell. 2. Atmospheric 
air strongly charged with it renders respiration difficult, causes 
unpleasant sensations, and produces catarrhal effects (by acting 
powerfully on the mucous membranes). Such air soon kills small 
animals, as mice, placed in it ; so that Ozone in its pure state must be 
highly deleterious to the animal economy. 3. It is insoluble in water, 
4. Like chlorine, bromine, and the metallic peroxides, it is a powerful 
electromotive substance. 5. It discharges vegetable colours with a 
chlorine-like energy. 6. It converts phosphorus ultimately into 
phosphoric acid ; it combines with chlorine, bromine, and iodine ; it 
does not unite with nitrogen under ordinary circumstances, but does 
when lime water is present ; and nitrate of lime is formed from which 
nitre may be readily obtained, 7. At common and even low tem- 
peratures it acts powerfully upon most metallic bodies, producing the 
highest degree of oxidation they are capable of. Lead and even 
silver is carried at once to the state of peroxides; arsenic and 
antimony produce arsenic and stibic acids. 8. It transforms many 
of the lower oxides into peroxides ; thus, the hydrate of the oxides of 
