LIGHT, 63 



shade over it, to secure an oxygenized current around it, and 

 wo have a light equal to gas. 



\\Y n.iisiiK-v light undor three divisions. 



First, light without heat or combustion. 



Second, light with heat and combustion. 



Third, how light is propagated. 



In the first division we have the aurora, fire-fliea, phosphor- 

 escence on water, etc. 



How are those lights caxised ? 



Merely by two cla3ses of suitable atoms, combining in suita- 

 ble proportions, and reciprocating, causing friction and light. 

 The aurora is caused by the mineral gases from the poles, or 

 in polar latitudes, mingling with the vegetable gases from 

 equatorial, or warmer latitudes, in certain proportions, and under 

 certain conditions. These same gases in other proportions 

 and conditions will produce rain and snow, lightning and 

 thunder, hail and storms ; so that it will be observed, nearly 

 everything depends upon proportion, condition and position. 



On the Pacific ocean, we have seen the waves, made by the 

 steamer, rolling in a volume of liquid fire, while a long stream of 

 light was left behind almost bright enough to read by ; yet there 

 was no more heat in it, than in the surrounding water. 



Why was this ? Because the atoms were not in a position to 

 produce and show a development of heat. 



If these light giving principles could be extracted from the 

 water, we have no doubt they might be placed in a position to 

 exhibit heat also. 



If merely cutting through the water lights it up, it may be 

 asked why does the water not always shine, seeing that the 

 light producing properties are always present in it 1 Because it 



