i8 " N RAYS 



Their common origin in the emission of an Auer 

 burner is favourable to such a view, as is also 

 the opacity of rock-salt and of water. But on 

 the other hand, for Auer rays, the transparency 

 of metals and other substances opaque to 

 Rubens' rays constitute an apparently radical 

 difference between the two sorts of radiations 

 (note 7). 



On New Sources of Radiations capable of 

 traversing Metals, Wood, etc., and on New 

 Actions produced by these Radiations (May 

 25> 1903). 



While investigating whether radiations 

 analogous to those whose existence I recorded 

 in the emission from an Auer burner (see p. 13) 

 are not to be met also in other sources of light 

 and heat, I established the following facts : 

 the flame of an annular gas-burner emits such 

 radiations ; the chimney, however, should be 

 removed, on account of the absorption of the 

 rays by glass. A Bunsen burner scarcely 



