142 
Are  They  Roentgen  Rays? 
(  Am.  Jour.  Pharm. 
t      March.  1  SI  6. 
ARE  THEY  ROENTGEN  RAYS? 
By  Edson  S.  Bastin. 
Years  ago,  when  the  writer  dabbled  somewhat  in  amateur  photo- 
graphy, he  observed  that,  when  his  plate-holders  containing  dry 
plates  were  exposed  to  direct  sunlight,  fogging  was  the  result.  It 
( 
Photograph  by  direct  sunlight  through  Opaque  Slide  of  Plate-Holder. 
was  then  supposed  that  the  plate  holders  must  have  been  defective; 
but  since  the  discovery  of  the  new  rays  by  Roentgen,  it  occurred  to 
the  writer  that  the  effects  observed  may  have  been  due  to  these 
rays  in  the  sunlight;  so  it  was  determined  to  subject  the  matter  to 
