134  Gleanings  from  the  German  Journals.  {AmMarch588a9rm' 
silver  nitrate  which  is  placed  over  the  generator ;  the  yellow  colora- 
tion formed  is  due  to  Ag3  As  3Ag  N03 ;  this  test  will  allow  of  the 
detection  of  0*001  mg.  As2  Oa.  Not  quite  so  delicate  but  a  more  con- 
venient test  is  gotten  by  using  mercuric  chloride  to  moisten  the  filter 
paper,  a  yellow  stain  is  also  produced,  but  its  nature  is  not  established ; 
0'002  mg.  As203  will  be  indicated  by  this  modification  which  has 
two  important  advantages  :  first,  AgNOs  is  affected  by  light,  HgCl2 
is  not  affected  to  any  marked  degree ;  second,  H3  Sb  does  not  stain 
HgCl2  while  it  does  stain  Ag  NOs.  In  alkaline  solutions,  by  use  of 
sodium  amalgam,  not  less  than  0*01  mg.  As203  can  be  detected; 
metallic  aluminum  with  an  alkali  did  not  give  good  results  as  it  con- 
tains either  S,  As  or  P,  which  interfere.  Other  metals  in  acid  solu- 
tion were  tried  but  none  were  found  superior  to  zinc.  To  test  the 
zinc,  lOgm.  are  acted  upon  by  dilute  HC1,  the  evolved  gas  should 
produce  no  yellow  stain  with  Ag  N03  or  Hg  Cl2  in  two  hours,  the 
test  to  be  made  in  a  dark  place.  The  manufacturers  of  zinc  are  asked 
to  produce  a  metal  absolutely  free  from  As,  Sb,  S  and  P. 
Aeetanilid  in  Phenacetin  to  the  extent  of  two  per  cent,  may  be 
proven  by  boiling  0*5  gm.  in  5-8  cc.  water,  allowing  to  cool,  filtering, 
adding  to  the  filtrate  dilute  nitric  acid  and  a  little  potassium  nitrite, 
boiling,  adding  several  drops  nitroso-nitric  acid  and  again  boiling  ;  a 
distinct  red  color  appears  in  presence  of  aeetanilid. — Schroeder  (Ned. 
Tydschr.  Pharm.)  Pharm.  Ztg.,  1889,  57. 
Assay  of  narcotic  extracts. — The  method  of  L.  van  Itallie  requires 
the  following  solutions:  Lead  acetate,  1:10;  dilute  sulphuric  acid, 
5:100 ;  chloroform ;  ether ;  i  normal  acid ;  and  as  indicators 
cochineal  tincture  or  an  alconolic  solution  of  azotlinin  or  lacmoid. 
For  the  examination  of  aconite,  belladonna  and  hyoscyamus  extracts, 
the  procedure  is  to  take  5  gm.  extract  which  is  rubbed  up  with  ten 
drops  dilute  sulphuric  acid  and  sufficient  water  to  make  50  cc.r 
allowed  to  macerate  one  or  two  hours,  and  25  cc.  of  the  lead  acetate 
solution  added.  After  the  subsidence  of  the  precipitate,  50  cc.  are 
filtered  off  through  a  dry  filter,  10  cc.  dilute  sulphuric  acid  added,  50 
cc.  filtered  into  a  separating  funnel,  sufficient  ammonia  added  to  give 
alkaline  reaction  and  the  alkaloid  extracted  by  use  of  three  portions  of 
chloroform  of  50  cc.  each.  The  mixed  chloroform  extractions  are 
distilled  to  dryness,  the  residue  taken  up  in  5  cc.  dilute  alcohol  and, 
after  adding  indicator,  titrated  with  XJ0  normal  acid.  The  acid  added 
represents  the  alkaloid  in  21  gm.  extract.    For  conium  extract  the 
