Amju°nUer;iP905arm"}     Use  of  Copper  in  Destroying  Typhoid.  269 
The  use  of  electricity  (12),  as  also  of  ozone  (13)  has  been  proposed. 
The  use  of  copper  (14)  for  the  purification  of  water  on  a  large 
scale  was  first  proposed  by  Dr.  Moore  and  Mr.  Kellerman,  in  a  bul- 
letin of  the  U.  S.  Department  of  Agriculture  a  year  ago.  In  a  sec- 
ond bulletin  issued  some  weeks  ago  the  authors  have  confirmed  the 
efficiency  of  copper  in  the  purification  of  water  contaminated  by 
algae.  They  also  report  in  one  instance  the  abatement  of  an  epi- 
demic of  typhoid  fever  in  New  Mexico,  a'ter  treatment  of  the  water- 
supply  with  copper  sulphate.  At  Columbus,  O.,  the  water  was 
treated  with  copper  sulphate  during  September,  October,  Novem- 
ber and  December,  when  the  number  of  typhoid  cases  was  reduced 
to  from  four  to  sixteen  per  month.  The  treatment  was  discontinued 
and  the  number  of  typhoid  cases  rose  from  91  to  376  per  month 
during  January,  February  and  March. 
That  copper  has  a  marked  toxic  or  oligodynamic  action  on  fecal 
bacteria,  including  typhoid  bacilli,  has  been  known  since  the  experi- 
ments of  Israel  and  Klingmann  1  were  reported  in  1897,  and  their 
observations  have  been  confirmed  by  Moore  and  Kellerman  and  by 
every  one  who  has  worked  along  these  lines  since.2  I  have  found  that 
when  copper  foil  is  allowed  to  remain  in  distilled  water  from  one  to 
five  minutes  sufficient  copper  is  dissolved  by  the  water  to  kill  typhoid 
organisms  within  two  hours. 
THE  EFFECTS  OF  COPPER  ON  LOWER  ANIMALS  AND  PLANTS. 
It  is  well  known  that  the  action  of  copper  salts  upon  both  plants 
and  animals  varies  quite  considerably.  Seeds,  for  example,  may  be 
treated  with  quite  concentrated  solutions  of  copper  sulphate  with- 
out impairing  their  germinating  activities.  I  have  sprayed  certain 
plants,  as  the  common  plantain  and  poison  ivy,  with  10  per  cent, 
copper  sulphate  solutions  without  noticing  any  ill  effects.  Very 
many  plants  withstand  spraying  with  solutions  of  copper  sulphate 
containing  as  much  as  I  part  per  1,000.  The  effects  vary  greatly 
according  to  the  conditions  which  surround  the  plant.  Seedlings 
of  pea  and  corn,  for  instance,  are  killed  when  placed  in  solutions  of 
copper  sulphate  I  part  to  200,000 ;  but  when  the  seedlings  are 
1  Virchow's  Archiv,  147,  1897,  pp.  293-340. 
2  See  papers  by  M.  E.  Pennington,  N.  Gildersleeve  and  A.  H.  Stewart  in 
American  Journal  of  Medical  Sciences,  May,  1905,  and  by  W.  P.  Mason } 
Science,  April  28,  1905. 
