190  Treatment  of  Human  Cancer.  {AmAp°rur'i9ih3arm' 
soluble  resin  and  ash  content.  The  U.  S.  P.  allows  an  ash  content 
of  not  over  15  per  cent.  No  .sample  approached  even  the  pharma- 
copceial  maximum  and  ten  contained  over  50  per  cent.  ash.  The 
ash  consisted  chiefly  of  calcium  sulphate.  Another  sample,  taken 
on  the  request  of  a  large  wholesaler  and  guaranteed  to  contain 
61.3  per  cent,  soluble  resin  and  16.675  Per  cent,  ash,  contained 
61.84  per  cent,  soluble  resin  and  17.18  per  cent,  ash,  showing 
that  a  high-grade  powdered  asafetida  is  by  no  means  an  impos- 
sibility, as  often  claimed. 
THE  TREATMENT  OF  HUMAN  CANCER  WITH 
INTRAVENOUS  INJECTIONS  OF  COLLOIDAL 
COPPER.1 
By  Leo  Loeb,  C.  B.  McClurg,  and  W.  O.  Sweek,  of  St.  Louis.2 
The  experimental  study  of  tumor  growth  which,  as  far  as  its 
methodical  and  continued  evolution  is  concerned,  originated  about 
twelve  years  ago,  made  possible  a  systematic  analysis  of  the  con- 
ditions on  which  the  life  and  growth  of  the  tumor  cells  depend,  and 
thus  laid  the  foundation  for  rational  investigation  aiming  at  the 
cure  for  cancer.  Within  the  last  decade  many  investigators  studied 
the  conditions  under  which  an  active  and  passive  immunity  against 
tumor  growth  can  be  established  in  the  animal  body,  and  the  effect 
of  Roentgen  rays  and  of  radium  on  tumor  growth.  One  of  us 
undertook,  in  1901  and  1902,  the  first  experiments  in  which  the 
effect  of  various  chemicals  in  vitro  on  the  vitality  of  tumor  cells 
was  analyzed.3  He  found  that  it  is  possible  to  obtain,  by  grading 
the  strength  of  such  a  substance  as  KCN,  a  gradual  decrease  in  the 
virulence  of  tumor  cells.  The  recent  work  of  v.  Wassermann  and 
his  collaborators  marks  a  most  important  step  in  advance  in  the 
treatment  of  carcinoma  in  mice.  They  found  that  a  combination 
of  selenium  and  eosin,  after  repeated  intravenous  injections,  caused 
a  rapid  retrogression  of  the  tumor.  The  effective  dose  was  very 
near  the  lethal  dose  of  the  substance.  Neuberg,  Caspari  and  Loehe 
observed  that  various  solutions  of  heavy  metals  caused  a  disappear- 
ance of  some  animal  tumors ;  but  they  do  not  state  explicitly  what 
1  From  the  Barnard  (Free)  Skin  and  Cancer  Hospital,  St.  Louis,  Mo. 
2  Reprinted  from  Interstate  Medical  Journal,  vol.  xix,  No.  12. 
"Leo  Loeb  (Virchow's  Archiv.  Bd.  172,  1903). 
