Alo cuSSer  ^9%™'  }  Monobromated  Camphor  in  Migraine  Tablets.  667 
washed  well.  (The  filtrate  can  be  tested  for  lead  by  B.P.  method.) 
The  copper  will  be  in  the  solution,  while  the  lead  (most,  if  not  all) 
will  be  in  the  precipitate. 
The  precipitate  is  washed  into  a  Nessler  cylinder  with  water, 
5  Cc.  of  dilute  acetic  acid  are  added,  followed  by  an  aqueous  solu- 
tion of  hydrogen  sulphide,  and  the  color  matched  in  the  usual 
manner. 
The  control  solution  is  prepared  as  follows : 
A  quantity  of  dilute  lead  solution  (B.P.)  diluted  with  water  is 
rendered  faintly  alkaline  with  ammonia,  and  to  this  is  added  5  Cc. 
dilute  acetic  acid  and  finally  hydrogen  sulphide  solution. 
The  following  results  were  obtained  by  the  above  method  on 
samples  prepared  by  adding  lead  to  a  food  containing  copper  and 
iron : 
Lead  Added.  Lead  Found. 
10  parts  per  million   8,    9  parts 
20    "       "       "    20,  16  " 
Sutton  Road,  Southend. 
ESTIMATION  OF  MONOBROMATED  CAMPHOR  IN 
MIGRAINE  TABLETS.1 
By  W.  O.  Emery. 
Introduction. 
The  estimation  of  monobromated  camphor  per  se  by  means  of  its 
bromine  content  may  be  effected  with  greater  or  less  facility  by  any 
one  of  several  procedures,  notably  the  classic  one  of  Carius ;  more 
speedily,  however,  by  that  of  StepanofT2  which  involves  reduction 
in  absolute  alcohol  with  sodium,  or  by  modifications  thereof  as  re- 
ported by  Bacon,3Maryott,4  and  Drogin  and  Rosanoff.5  The  earliest 
recorded  experiments  dealing  specifically  with  the  quantitative  elim- 
ination of  the  halogen  in  monobromated  camphor  were  undertaken 
1  Reprinted  from  The  Journal  of  Industrial  and  Engineering  Chemistry, 
August,  1919. 
2  Ber.,  39  (1906),  4056. 
3 /.  Am.  Chem.  Soc.,  31  (1909),  49. 
*  A  m.  J.  Sci.,  30  (1910),  378;  Chem.  News,  103  (1911)  I. 
5  J.  Am.  Chem.  Soc.,  38  (1916),  711. 
