34)6 Scientific Proceedings, Royal Dublin Society. 



Hence iii order that these miglit be equal we must have — 



a=:l-l X 104 X A. 

 Now in the case of Hydrogen at the usual temperature and pressure — 



A =8-8 X 10-5 . 



so that — 



a='96, 



or it woiild have to absorb 96 per cent, of the radiations that fell on it. 

 From this it seems almost certain that this repulsion can have hardly 

 any effect on the motion of gases under the action of the sun. As how- 

 ever but little is known of the thickness of the layer of gas that will 

 absorb all the heat that the gas will easily absorb, it may be premature 

 to decide finally upon the question. 



