AmMa^i£3.arm'}    Recent  Literature  Relating  to  Pharmacy.  227 
salts  of  this  element,  induced  Madame  and  Monsieur  Curie  to  try 
and  separate  out  from  pitchblende  that  portion  to  which  the  added 
radioactivity  was  due. 
After  considerable  experimenting  they  were  able  to  separate  out 
a  body  that  had  the  physical  properties  of  bismuth,  but  was  at  least 
100  times  more  radioactive  than  uranium.  From  the  fact  that 
ordinary  bismuth  salts  did  not  show  any  radioactive  properties  the 
Curies  came  to  the  conclusion  that  in  this  case  the  radioactivity 
was  due  to  some  new  elementary  body  to  which  they  gave  the 
name  polonium,  from  Poland,  the  native  country  of  Madame  Curie. 
According  to  W.  Marckwald,  who  has  devoted  a  considerable 
amount  of  time  to  the  investigation  and  study  of  this  substance, 
the  radioactive  portion  of  the  bismuth  salt  is  closely  related  to  tel- 
lurium; he  therefore  calls  it  radioactive  tellurium.  Marckwald  also 
states  that  the  rays  emitted  by  radioactive  tellurium,  or  polonium 
as  it  is  still  called  in  France,  are  composed  largely  if  not  entirely  of 
A-rays.  They  ionize  gases,  affect  photographic  plates,  and  are 
readily  absorbed  by  all  substances,  even  paper.  Many  phosphores- 
cent bodies  are  lit  up  brightly  when  brought  near  or  in  contact  with 
this  substance.  One  peculiar  property,  noted  by  Marckwald,  is  that 
when  a  genuine  diamond  is  brought  near  or  in  contact  with  a  small 
quantity  of  polonium  it  lights  up  brightly,  the  visible  light  being 
sufficient  to  cause  change  in  photographic  plates.  O.  Rosenheim 
(Client.  News,  1902,  page  247)  substantiates  this  assertion,  but  says 
that  the  so-called  black  diamonds  are  an  exception  to  this  rule.  He 
also  says  that  the  phosphorescent  rays  emitted  by  the  diamond  will 
affect  photographic  plates  and  are  distinguishable  from  the  rays 
emitted  by  polonium  itself  in  that  they  penetrate  paper  and  glass. 
The  phosphorescence  ceases  as  soon  as  the  polonium  is  removed. 
Radium. — Soon  after  the  discovery  of  polonium  the  Curies  found 
another  substance  in  pitchblende  that  was  strongly  radioactive;  this 
substance  they  called  radium.  Radium  has  been  generally  accepted 
as  a  new  addition  to  the  list  of  elements;  it  appears  to  have  proper- 
ties somewhat  resembling  barium,  from  which  it  is  with  difficulty 
separated.  Madame  Curie  (Compt.  Rend.,  1902,  page  161)  has  been 
able  to  separate  out  a  small  quantity  of  pure  radium  chloride,  by 
fractional  crystallization.  E.  Demarcay  has  determined  the  purity 
of  this  sample  by  means  of  the  spectroscope  and  found  that  it  did  not 
contain  the  spectrum  of  any  other  known  element. 
