46 " N RA YS 



in the above-described experiments the brick 

 can be replaced by a vase of thin glass, filled 

 with salt water, and previously exposed to the 

 sun's rays ; the effect is very marked. It is 

 certainly due to the salt water, for the empty 

 vase is without effect. This is a unique example 

 of a phosphorescence phenomenon in a liquid 

 body. It is true that the wave-lengths of " N " 

 rays are very different from those of luminous 

 rays, as results from measurements which it is 

 my intention to describe very soon. 



The eye of an ox, killed the day before, rid 

 of its muscles and the tissues adhering to the 

 sclerotic, proved to be transparent to " N " rays 

 in all directions, and became itself active by 

 sun-exposure ; it is the storing-up of the " N " 

 rays by the media of the eye which causes the 

 retardation observed in the appearance and 

 cessation of the phenomena which are the 

 subject of the present note. 



Sea- water and the stones exposed to solar 

 radiation store up " N " rays which they after- 

 wards restore. Possibly these phenomena play 

 some hitherto unperceived part in certain ter- 

 restrial phenomena. Perhaps, also, " N " rays 



