292  Disinfection  with  Formaldehyde.    {Ani j?^' f£%rm' 
DISINFECTION  WITH  FORMALDEHYDE. 
A  SUBSTITUTE  FOR  THE  PERMANGANATE-FORMALIN 
METHOD.1 
By  C.  G.  Storm. 
The  method  proposed  by  H.  D.  Evans  and  J.  P.  Russell  in  19042 
for  the  rapid  liberation  of  formaldehyde  gas  from  its  water  solution, 
the  "  formalin  "  of  commerce,  in  a  condition  suitable  for  practical 
disinfection,  has  been  found  by  numerous  investigators  to  be  su- 
perior to  most  of  the  other  known  methods  of  formaldehyde  disin- 
fection, as  regards  simplicity,  rapidity,  cost  and  efficiency.  This 
method  consists  in  pouring  the  formalin  quickly  upon  crystals  of 
potassium  permanganate  contained  in  any  suitable  metallic  vessel 
(for  example,  a  water  bucket),  the  oxidation  of  a  part  of  the  for- 
maldehyde furnishing  sufficient  heat  to  cause  rapid  evaporation  of 
the  remainder  of  the  formaldehyde  together  with  the  water. 
The  permanganate  method  has  found  very  general  application 
and  is  widely  used  in  this  country  in  practical  disinfection  work. 
Its  use  has,  however,  received  a  serious  set-back  by  reason  of  the 
present  scarcity  of  potassium  permanganate  and  the  resulting  ex- 
cessive cost  of  this  chemical.  Prior  to  the  war  in  Europe,  potas- 
sium permanganate  was  obtainable  in  this  country  at  prices  ranging 
usually  from  9  to  10  cents  per  lb.  It  is  now  obtainable  only  at  many 
times  its  former  price,  having  held  at  approximately  $4.00  to  $4.25 
per  lb.  for  the  past  six  months. 
This  fact  has  impressed  the  writer  with  the  desirability  of  pub- 
lishing a  note  regarding  an  analogous  method  for  generating  for- 
maldehyde, devised  by  him  in  October,  191 1,  which  it  is  believed  has 
never  been  proposed  for  practical  use,  which  preliminary  tests  in- 
dicate to  be  safer,  as  rapid,  and  almost  as  simple  of  operation,  and 
which  will  be  much  less  expensive,  owing  to  the  relatively  low  price 
of  the  material  used. 
The  new  method  depends  upon  the  action  between  the  water 
1  Reprinted  from  The  Journal  of  Industrial  and  Engineering  Chemistry, 
February,  1918. 
2  H.  D.  Evans  and  J.  P.  Russell,  "Formaldehyde  Disinfection,"  13th  Ann. 
Rept.,  State  Board  of  Health  of  Maine,  and  /.  Am.  Chem.  Soc.,  27  (1905),  714. 
See  also  Daniel.  Base,  "  Formaldehyde  Disinfection,"  /.  Am.  Chem.  Soc.,  28 
(1906),  964-96. 
