360  Dettction  of  Saccharin  in  Beer.  {^"""/uiy^im^'''^* 
about  90  grains.  This  relationship  indicates  that  the  saccharin  has 
about  200  times  the  sweetening  power  of  sugar. 
When  heated^  saccharin  partially  sublimes,  giving  vapors  of  an 
intensely  sweet  taste.  If  heated  in  admixture  with  caustic  soda  to 
250°  C.  it  forms  salicylic  acid,  which  can  be  detected  by  dissolving  the 
residue  in  acidulated  water,  agitating  with  ether,  evaporating  the 
ethereal  solution  of  dryness,  and  adding  ferric  chloride,  when  the 
characteristic  violet  coloration  is  produced.  When  saccharin  is  ignited 
in  admixture  with  caustic  or  carbonated  alkali,  preferably  with  addi- 
tion of  a  little  oxidizing  agent,  such  as  nitre,  it  yields  a  residue  con- 
taining sulphate,  which  of  course  can  be  detected  by  adding  chloride 
of  barium  to  the  acidulated  solution.  The  weight  of  sulphate  of 
barium  precipitated,  if  multiplied  by  0"785,  gives  the  weight  of  sac- 
charin to  which  it  corresponds. 
An  aqueous  solution  of  saccharin  when  heated  with  potassium  ferri- 
cyanide  becomes  colored  apple-green,  an  odor  of  hydrocyanic  acid 
being  evolved. 
Saccharin  is  extracted  with  tolerable  facility  on  agitating  its  acidu- 
lated aqueous  solution  with  ether. 
Utilizing  these  reactions  I  have  found  no  difficulty  in  detecting  less 
than  J  grain  of  saccharin  in  one  pint  of  beer.  The  beer  was  concen- 
centrated  to  about  one-third,  and  at  once  agitated  with  ether.  As  a 
matter  of  fact,  I  added  a  little  phosphoric  acid,  but  this  precaution 
was  superfluous,  as  the  liquid  had  already  a  marked  acid  reaction. 
Acidulation  with  sulphuric  acid  is  not  desirable.  The  ethereal  solution 
left  on  evaporation  is  a  residue  which  was,  of  course,  intensely  bitter 
and  was  not  adapted  for  the  recognition  of  saccharin  by  any  test  other 
than  the  production  of  sulphate  on  ignition  in  the  presence  of  alkali. 
By  this  method,  however,  distinct  evidence  of  the  presence  of  saccharin 
was  obtained,  whereas  a  blank  experiment  on  the  same  beer,  to  which 
no  saccharin  had  been  added,  failed  to  show  any  trace  of  sulphates  by 
the  same  process. 
A  purer  residue  is  obtained  by  treating  the  beer  with  acetate  of  lead 
and  filtering  before  agitating  with  ether.  There  is  no  occasion  to 
remove  the  excess  of  lead,  and  in  fact  the  use  of  sulphuretted  hydrogen 
would  be  very  undesirable. 
It  will  be  seen  that  the  detection,  and  even  the  determination  of 
saccharin  in  beer  presents  no  great  insurmountable  difficulty,  even  in 
the  presence  of  salicylic  acid.     I  do  not  know  of  any  organic  sub- 
