Am  Jour  Pharm.)  Valuation  of  Tartar  Emetic.  417 
August,  1884.     j  «/ 
gas,  which  turns  it  black  ;  caustic  alkalies  and  Alkaline  mono-carbonates 
stain  it  greenish-brown  to  black,  whilst  the  alkaline  bicarbonates  leave 
it  colorless. 
Silver  bichromate  paper  turns  yellow  with  free  hydrochloric  acid. 
Besides  these  the  author  mentions  a  number  of  other  papers  less 
frequently  needed.  The  use  of  all  consists  in  letting  a  drop  of  the 
liquid  in  question  fall  upon  a  slip  of  the  paper. 
The  author  tests  for  arsenic  (arsenious  and  arsenic  acids)  by  means 
of  slips  of  sheet  brass,  2*5  to  3  centimetres  in  length  and  15  to  17 
centimetres  in  length.  The  hydrochloric  solution  is  mixed  with  a  little 
oxalic  acid,  or  the  ammonical  solution  is  supersaturated  with  hydro- 
chloric acid  and  mixed  with  oxalic  acid  in  order  to  reduce  arsenic  to 
arsenious  acid.  A  drop  of  the  solution  is  put  upon  a  brass  plate  and 
sharply  dried ;  the  place  of  the  drop  is  then  washed  with  water,  when 
a  dark  spot  of  a  permanganate  color  reveals  the  presence  of  arsenic. 
Dark  thin  outlines  still  appear  in  case  of  dilution  with  150,000  parts. 
In  cases  where  the  papers  and  the  brass  plate  are  not  used  the  author 
places  the  two  drops  (of  the  reagent  and  the  liquid  in  question)  near 
each  other  upon  a  slip  of  glass  and  mixes  them.  The  transparency 
of  the  glass  renders  the  slightest  turbidity  visible. — Pharmaceut.  Cen- 
tral-Halle and  Chemiker  Zeitung ;  Chem.  News,  July  4,  1884,  p.  6. 
THE  VALUATION  OF  TAETAR  EMETIC.1 
By  W.  B.  Hart. 
The  adulteration  and  consequent  lessening  of  the  valuable  ingredient 
in  drugs  and  dye-wares  tends  to  develop  methods  of  analysis,  by  which 
the  commercial  value  of  them  may  be  rapidly  determined,  and  thus 
the  user  and  honest  manufacturer  be  protected.  Tartar  emetic,  whose 
value  to  the  dyer  depends  solely  on  the  amount  of  antimony  it  contains, 
has  of  late  been  lowered  in  quality,  until  in  some  cases  it  contains  only 
about  one-half  the  amount  of  metal  that  a  good  commercial  sample 
should  have.  The  usual  method  of  estimating  the  antimony  in  this 
salt  is  by  means  of  a  standard  solution  of  iodine,  as  recommended  in 
most  volumetrical  analysis  manuals.  This  method  gives  good  results 
in  careful  and  patient  hands,  but  I  find  that  it  can  be  well  replaced  by 
a  solution  of  calcic  hypochlorite,  or  common  bleach  liquor,  of  a  strength 
1  From  the  "Journal  of  the  Society  of  Chemical  Industry,"  May  29,  1884. 
27 
