256 



dry or wet, and paraffin do not store up the rays. He found that one 

 of the essential conditions of a substance that stores up the rays is 

 dryness. It is found that briclvs exposed to sunlight become a source 

 for hours afterward. 



While experimenting- along this line Blondlot discovered an unex- 

 pected effect. While viewing a strip of white paper Avhich was feebly 

 illuminated, a brick which had been exposed to sunlight was brought 

 near the eye and the outline of the paper became more distinct. The 

 intensity diminished when the brick Avas removed. A clock face which 

 seemed a grey patch on the wall became clearly outlined and the hands 

 visible when a brick Avas brought near the eye. Water intercepts the 

 radiation, in fact, Blondlot used dampened paper as screens in his work. 

 Salt water transmits the rays. An ox eyii was transparent and became 

 a secondary source. Hyposulphite of soda in solid or solution is found 

 to be a powerful accumulator. Blondlot has found that compressed glass, 

 wood, etc., emit N-rays and cause the phosphorescent screen to become 

 more luminous. A bent cane near the head caused a clock to become 

 more visible. Unbending the cane caused the clock to disappear. Tem- 

 pered objects, such as tiles, knife blades, hammered brass, had the same 

 effect, as also did a knife blade from an ancient tomb. The rays are 

 emitted from nearly every strained object. In fact F. E. Hackett (Roy. 

 Dublin Soc. Trans. S. 10. pp. 127-138, Sept. 10(i4|. the only English speak- 

 ing person who is sure he has observed the effect, recommends the use 

 of cork or wood under pressiu'e as a source. 



In the early part of the present year Blondlot finds that he has been 

 dealing with two distinct kinds of radiation. N-rays cause the calcium 

 sulphide screen to become more luminous, while the second radiation, 

 or Ni-rays cause the normal intensity to decrease. N-rays cause the 

 normal intensity from the screen to increase, while Nj-rays cause the 

 tangential radiation of the screen to V)ecome more luminous. 



Photographs have lieen published wliu-h sliow a greater effect on 

 the plate under the influence of the N-rays than that without. For these 

 photographs, in every case, the light from the little spark gap is used. 

 A. Charpentier has found that the human body is a source of N-rays, 

 the intensity being greater near the nerve centers. The spinal column 

 can be traced by means of the screen. Certain parts of the brain give off 

 the rays abundantly. Tlie intensity being greatly augmented when the 

 l)rain is active. Charpentier c.-ni see liimstlf tliiiU<. To refute those who 



