THE REASON WHY. 143 



" The voice of the Lord is upon the waters : the God of glory thundereth ; the 

 Lord is upon many waters." PSALM xxix. 



629. Why do electric storms purify the air? 



Because they restore the equilibrium of electricity which is 

 essential to the salubrity of the atmosphere; they intermix the 

 gases of the atmosphere, by agitation ; they precipitate the v apours 

 of the atmosphere, and with the precipitation of vapours, noxious 

 exhalations are taken to the earth, where they become absorbed ; 

 they also contribute largely to the formation of ozone, which 

 imparts to the air corrective and restorative properties. 



630. What is ozone ? 



Ozone is an atmospheric element recently discovered, and respect- 

 ing which differences of opinion prevail. It is generally supposed 

 to be oxygen in a state of great strength, constituting a variety of 

 form or condition. 



631. Why do we know that electricity contributes to the 

 formation of ozone ? 



Because careful observations have established the fact that the 

 proportion of ozone in the atmosphere is relative to the amount of 

 electricity. 



632. What are the properties of ozone? 



It displays an extraordinary power in the neutralisation of putre- 

 factions, rapidly and thoroughly counteracting noxious exhalations ; 

 it is the most powerful of all disinfectants. 



Schonbien, the discoverer of ozone, inclines to the opinion that it is a new 

 chemical clement. Whatever it may be, there can be no doubt that it plays an 

 important part in the economy of nature. Its absence has been marked by 

 pestilential ravages, as in the cholera visitations ; and to its excess are attributed 

 epidemics, such as influenza. It was found, during the last visitation of cholera, 

 that the fumigation of houses with sulphur had a remarkably efficacy in 

 preventing the spread of the contagion. The combustion of sulphur ozonised 

 the atmosphere ; the same result occurs through the emission of phosphoric 

 vapours; ozone is also developed by the electricity evolved by the electrical 

 machine, and in the greater electrical phenomena of nature. The smell 

 imparted to the air during an electric storm is identical with that which occurs 

 in the vicinity of an electrical apparatus it is & fresh and sulphurous odour. 

 The opinion is gaining ground that the respiration of animals and the combustion 

 of matter are sources of ozone, and that plants produce it when under the 

 influence of the direct rays of the sun. It is also believed to be produced by 

 water, when the sun's rays fall upon it. The most recent opinion respecting 

 ozone is, that it is electrized oxygen. The subject is of vast importance, and 

 opens another field of discovery to tho pioneers of scientific truth. 



