ADeceXrPi9i5m'}  Relations  of  Plants  to  Distilled  Water.  551 
starch  formation,  could  not  be  carried  on  and  that  therefore  deteriora- 
tion resulted.  He  also  believed  that  calcium  was  necessary  for  the 
transfer  of  the  reserve  materials  from  the  cotyledons  to  the  forma- 
tive organs.  Deherain  repeated  Boehm's  experiments  and  confirmed 
his  results. 
Owing  to  the  fact  that  even  distilled  water,  which  had  been  un- 
questioningly  regarded  as  pure,  produced  effects  simulating  toxicity, 
a  great  deal  of  attention  has  been  given  in  the  past  to  the  chemical  and 
other  properties  of  water  distilled  from  different  kinds  of  apparatus 
and  under  various  conditions.  On  the  animal  side,  workers,  among 
whom  may  be  mentioned  Kolliker  ('56)  and  Nasse  ('69),  had  early 
noticed  the  injurious  effects  on  tissues  when  the  same  were  placed  in 
distilled  water.  Nasse,  for  example,  found  the  deleterious  effect  of 
distilled  water  about  equal  to  that  of  the  following  solutions :  2.5  per 
cent.  NaCl,  3.3  per  cent.  NaBr,  3.7  per  cent.  Na2S04,  and  5.0  per 
cent.  Nal. 
Nageli  ('93),  in  his  classical  work  published  twelve  years  after 
his  death,  found  that  very  minute  amounts  of  toxic  substances, 
notably  copper,  in  solution  produced  injurious  effects  on  organisms 
(Spirogyra) ,  and  to  this  phenomenon  he  applied  the  term  "  oligo- 
dynamik  "  action.  This  line  of  work  was  extended  to  include  other 
substances  and  other  organisms,  and  claimed  the  attention  at  dif- 
ferent times  of  Aschoff  ('90),  Loew  ('91),  Locke  ('95),  Ringer 
('97),  Copeland  and  Kahlenberg  ('99),  Deherain  and  Demoussy 
('01),  Lyon  ('04),  Bokorny  ('05),  Hoyt  ('13),  and  others.  It  is  of 
particular  interest  to  note  that  Ringer  in  some  of  his  earlier  work 
ascribed  the  injury  to  the  extraction  from  the  organism  of  necessary 
nutrient  materials ;  but  after  the  publication  of  Locke's  experiments 
('95),  which  Ringer  duplicated  and  confirmed,  the  latter  concluded 
that  the  injury  done  in  the  particular  case  under  consideration  (Tubi- 
fex)  was  due  to  deleterious  materials  in  the  distilled  water.  He  says  : 
"  Copper  in  even  infinitesimal  quantities  will  disintegrate  tubifex 
whilst  water  free  from  copper  or  other  heavy  metals  and  without  any 
salts  such  as  calcium  salts  can  sustain  the  life  of  tubifex." 
In  regard  to  the  third  idea  pertaining  to  the  effects  of  distilled 
water  on  organisms,  early  workers,  both  on  the  plant  and  animal 
side,  found  that  salts  were  extracted  from  organisms  placed  in 
distilled  water,  even  though  their  methods  for  determining  the  ex- 
traction were  somewhat  crude.  Among  the  early  investigators  on 
the  animal  side  may  be  mentioned  Plateau  ('83),  Ringer  and  his 
