378 THE CANADIAN NATURALIST. [June 



conditions were fulfilled, the test papers showed the presence of 

 Ozone, thus demonstrating that neither electricity nor oxygen 

 alone, was sufficient to cause any change in the test papers- 

 From these facts it has received the name of electrified oxygen. 



Ozone can -be made artificially by taking a piece of phos- 

 phorus, about half an inch long, cleaning its surface by scraping, 

 putting it into a clean quart bottle, and adding as much water 

 as will cover half the surface of the phosphorous ; close the 

 bottle with a loose fitting stopper, and set it aside at a tempera- 

 ture of about 60° Fahrenheit ; Ozone will soon then begin to 

 form in the bottle, and in five or six hours it will be abundant. 

 Remove the phosphorus, shake a little water in the bottle, and 

 throw this out to remove the phosphoric acid. This washing 

 must be repeated several times ; the Ozone will not be washed 

 away but will remain with the atmospheric air in the bottle. 

 Oil of turpentine, exposed to the sun's rays, in a bottle, partly 

 filled, will also generate Ozone ; also some other chemical combina- 

 tions. The chemical agencies of magnetism and galvanism evolve 

 Ozone, and a current of electricity passed across the surface of 

 water produces it. It might be stated in reference to the formation 

 of Ozone by phosphorus, that the atmospheric air in the vessel 

 should be of the average barometrical pressure, and of a tempera- 

 ture not under 50° or over 90°, for Ozone is not formed in this 

 artificial way at zero Fahrenheit. The formation becomes very 

 rapid at 75° Fahrenheit. It is also formed by the ordinary 

 electrical machine in rapid motion, when the electric fluid is 

 evolved from the conductor — which fact, as before stated, led to 

 its discovery. It may also be formed in various other ways, but 

 enough for our present purpose. When formed by the decom- 

 position of water by means of the galvanic pile, Ozone is always 

 manifest at the positive pole. 



I shall now proceed briefly to state the means used to ascer- 

 tain its presence, and its amount in the atmosphere. The 

 method of detecting its presence is by means of a combination 

 of the iodide of potassium and starch. Take one part of iodide 

 of potassium, ten parts of starch, and 100 parts of water; 

 boil the starch with the water, allow the water to cool, and 

 stir intimately with it the iodide of potassium ; then spread the 

 mixture on slips of good glazed paper by means of a soft brush 

 or a sponge. My experience is that good glazed or sized paper is 

 preferable to bibulous or blotting paper. Cream-laid post has been 



