338 
Pharmaceutical  Assaying. 
Am.  Jour.  Pharrti. 
July,  1889. 
last  year's  meeting  to  bring  my  first  contribution  on  "  Opium  and  its  pre- 
parations." It  has  since  that  time,  however,  been  impossible  for  me  to 
continue,  as  originally  intended,  this  systematic  work,  owing  to  many 
disturbances,  and  so, — though  very  reluctantly, — I,  for  the  time,  have 
had  to  abandon  it,  to  be  taken  up  again  with  renewed  vigor,  however, 
as  soon  as  time  and  opportunity  shall  permit. 
The  present  paper  will  confine  itself  to  the  discussion  of  some  drugs 
and  preparations,  with  which  the  writer  has  been  kept  busy  during 
the  past  year.  In  some  of  these  cases  the  U.  S.  P.  does  not  offer 
"  tests,"  but  the  law  allows  the  Board  of  Health  to  enforce  conformity 
to  some  other  standard  in  such  a  case,  as,  e.  g.,  United  States 
Dispensatory,  National  Dispensatory,  or  even  any  other  well  qualified 
authority. 
Paregoric,  V.  S.  P. — Prepare  a  "  standard"  (strictly  U.  S.  P., 
using  standard  ingredients  ! )  for  comparison  with  the  suspected  sample 
through  the  following  tests  : 
1.  Acidity. — 20  cc.  of  sample  dilute  with  20  cc.  diluted  alcohol,  ti- 
trate with  J^TLNaHO  solution,  using  phenol phthalein  as  indicator 
(Drescher).  Standard  paregoric,  U.  S.  P.,  1880,  will  consume  7- 
8.5 cc.  ^nNaHO. — N.  B.  A  blank  experiment  with  the  diluted  alco- 
hol, used  in  the  preparation,  may  be  made,  and  allowance  made  for 
possible  acidity  of  it. 
2.  Sp.  gr.  is  approximately  0'925  to  0*935  (Drescher). 
3.  Morphiometric  assay  is  not  practicable. 
4.  Meconic-Acid  Determination : — Allen's  colorimetric  method  (es- 
pecially for  U.  S.  P.  article)  yields  uncertain  results.  Drescher's  mod- 
ification yields  fair  results,  thus  :  Evaporate  20  cc.  of  sample  on 
water-bath  with  1  gm.  freshly  ignited  kaolin  to  10  cc,  filter,  dilute 
filtrate  with  water  to  20  cc,  add  3  drops  10  per  cent,  ferric  chloride 
solution,  and  compare  coloration  with  that  of  the  standard  equally 
treated  (Drescher). 
5.  Foreign  Colors : — Caramel,  red  santal,  cochineal  are  commonly 
employed  ;  cudbear  rarely.  Solution  of  basic  lead  acetate  precipitates 
cochineal,  santal,  and  cudbear.  The  precipitate  may  be  freed  from 
lead  by  means  of  dilute  sulphuric  acid,  and  the  color  taken  up  by  a 
suitable  solvent  and  further  tested.  Caramel  is  best  precipitated  by 
kaolin  (freshly  ignited),  shaken  out  with  water,  and  evaporated,  or, 
the  tincture  may  be  directly  evaporated  down,  and  the  caramel  found 
in  the  residue,  as  a  black  or  brown,  viscid,  sweetish  mass,  after 
