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MORE  POISON  IN  "SODA  WATER." 
MORE  POISON  IN  "  SODA  WATER." 
By  John  T.  Plummer,  M.  D. 
One  of  our  apothecaries  Laving  just  fitted  up  a  new  soda- 
fountain,  presented  me  with  a  glass  cf  its  sparkling  contents 
projected  upon  raspberry  syrup.  After  the  pungency  of  the 
carbonic  acid  had  passed  off,  there  remained  in  my  mouth 
a  very  sensible  metallic  taste,  which  was  so  persistent  that  it 
lasted  several  hours.  I  remembered  that  the  whole  apparatus 
was  new ;  and  believed  that  the  impression  left  upon  my  tongue 
was  not  due  to  the  quality  of  the  syrup  used. 
Not  satisfied  with  any  explanation  that  presented  itself  to  my 
mind,  I  returned  to  the  store,  and  called  for  a  glass  of  the  clear 
water  without  syrup.  A  somewhat  mawkish,  metallic  taste  was 
very  apparent  to  all  who  sipped  it. 
What  occasioned  the  flavor  in  question  ?  Could  drippings  of 
copper  have  been  left  in  the  "  fountain?"  Or  a  part  of  the 
fountain  have  escaped  the  tinning,  leaving  the  copper  exposed 
to  the  action  of  the  carbonic  acid  ?  Or  was  the  taste  due  to 
copper  at  all  ? 
Eerro-cyanide  of  potassium  added  to  the  water  produced  a 
discoloration,  varying,  by  time,  from  a  yellowish  to  a  yellowish 
green,  greenish,  and  bluish  hue.  No  precipitate  followed.  The 
addition  of  dilute  sulphuric  acid  made  no  perceptible  difference 
in  the  action  of  the  re-agent.  I  then  proceeded  more  systemati- 
cally. 
1.  One  pint  of  the  clear  soda-water  was  evaporated  in  a  Ber- 
lin dish  to  two  ounces.  A  white  film  appeared  during  evapora- 
tion, on  the  surface  of  the  water  and  the  sides  of  the  vessel. 
This  was  probably  carbonate  of  lime,  from  our  limestone  water. 
There  was  also  a  slight,  light-brown  deposit  of  what  I  sup- 
posed was  vegetable  or  other  organic  matter.  As  silver,  lead, 
copper  and  tin  were  the  metals  which  constituted  the  apparatus, 
I  tested  the  liquid  remaining  in  the  capsule  in  reference  especial- 
ly to  them. 
2.  Hydrochloric  acid  was  added  to  the  condensed  fluid,  and 
the  mixture  warmed.  No  precipitate  followed.  The  absence  of 
silver,  mercury  and  probably  lead,  was  inferred. 
3.  In  the  already  acidulated  liquid,  I  suspended  a  bright 
needle.    A  scarcely  perceptible  tarnish  appeared  on  it. 
