Am.  Jour.  Pharm.  ) 
March,  1914.  / 
Current  Literature. 
143 
CURRENT  LITERATURE. 
The  Bad  Taste  in  Hypochlorite-treated  Water-supplies. — 
It  is  surprising,  as  pointed  out  by  Lederer  (Proc.  III.  W ater  Supply 
Assn.,  1913,  p.  235),  that  so  little  attention  has  been  paid  to  the 
question  of  removing  the  taste  from  water-supplies  treated  with 
chlorinated  lime.  In  this  country,  especially,  where  the  treatment 
of  many  large  public  supplies  has  been  carried  out  with  brilliant 
sanitary  success,  there  has  been  frequent  and  often  bitter  complaint 
about  the  taste  of  the  treated  water.  As  well  known,  antagonism  has 
developed  in  many  places  between  water  boards  and  health  depart- 
ments as  a  result  of  these  conditions.  On  one  side  is  the  recognition 
that  the  danger  from  water-borne  diseases  is  greatly  reduced  by 
hypochlorite  treatment:  on  the  other  is  the  necessity  of  having  to 
bear  the  burden  of  daily  complaint  and  to  meet  the  indignant  protests 
of  thousands  of  aggrieved  water-drinkers.  As  pointed  out  by 
Lederer,  a  simple  method  is  available  for  removing  the  taste  from 
hypochlorite-treated  water.  After  careful  experimenting  he  has 
confirmed  the  advantage  of  sodium  thiosulphite  (Na2S203,  5H20)  as 
recommended  by  Bruns.  The  reaction  on  the  residual  chlorin  is  as 
follows :  Na2S203+  8C1  +  5ILO  =  Na2S04+  H2S04+  8HC1.  The 
acids  formed  in  the  neutralization  process  immediately  combine  with 
bases  to  form  neutral  salts.  Lederer  has  obtained  good  results  in  the 
elimination  of  taste  in  Lake  Michigan  water  treated  in  this  way. 
Sodium  thiosulphate  seems  to  possess  -  marked  advantages  over 
sodium  sulphite.  It  must  be  remembered  that  the  action  of  the 
thiosulphate  stops  the  germicidal  action  of  the  chlorin  so  that  it  is 
necessary  to  allow  the  chlorin  to  act  for  a  sufficient  length  of  time 
(Lederer  recommends  from  at  least  ten  to  fifteen  minutes)  before 
the  thiosulphate  is  added.  An  interesting  point  brought  out  in  the 
discussion  of  Lederer's  paper  is  that  hypochlorite  seems  under 
some  conditions  to  accentuate  an  unpleasant  taste  originally 
present  in  the  water.  In  Toledo,  for  instance,  it  is  stated  that  the 
water  develops  a  disagreeable  taste  when  the  river  first  freezes  over, 
owing  to  the  presence  of  large  amounts  of  vegetable  matter  in  the 
water.  The  bad  taste  is  said  to  be  increased  by  even  small  amounts 
of  hypochlorite. — Jour.  A.  M.  A.,  vol.  lxi,  No.  16,  October  18,  1913, 
p.  1464. 
