28 EFFECTS OF 



2ndly Because the agitation of the 

 storm stirs up the air, 



Q. How does the production of nitric acid 

 purify the air ? 



A. Nitric acid acts very powerfully in 

 destroying exhalations, arising from putrid 

 vegetable and animal matters. 



Q. Why is LIGHTNING more common in 

 SUMMER and AUTUMN, than in spring and winter? 



A. The heat of summer and autumn 

 produces great evaporation; and the 

 conversion of water to vapour, always 

 develops electricity. 



Q. Why does a THUNDER-STORM generally 

 follow very DRY weather, and rarely succeeds 

 continued WET ? 



A. The clouds are always charged 

 with electricity ; but dry air (being a non- 

 conductor), will not conduct the surplus 

 fluid from the clouds to the earth : so 

 it violently rends the dry air with a flash, 

 in order to relieve the cloud, and reach 

 the earth. 



Q. What is the general DIRECTION of a 



THUNDER-STORM 



A. Either from east to west ; or else 

 from north to south. 



