AMjaa.ur;m3ARM'  }     Silver  in  Subnitrate  of  Bism  u  th  ,  21 
spirit,  and  with  its  complication.  This  is  to  some  extent  true,  and  I 
should  be  the  last  to  do  so  if  no  practical  results  were  to  be  gained, 
but  it  must  have  occurred  to  many  persons  as  being  somewhat  incon- 
sistent that  in  the  B.  P.  we  should  have  but  two  strengths  of  spirit 
(and  these  more  or  less  arbitrary)  as  being  best  capable  of  dissolving 
and  preserving  the  active  principles  of  the  whole  materia  medica. 
Syrup  of  Orange  Peel.— Most  of  what  I  have  written  with  re- 
gard to  the  tincture  from  fresh  peel  will  apply  to  the  syrup  made  from 
that  tincture,  but  with  this  exception,  it  does  not  lose  anything  of  its 
fine  aroma  by  age.  Sugar  appears  to  possess  a  preservative  influence, 
and  this  suggests  an  experiment  worth  trying  when  Seville  oranges 
are  again  in  season,  viz.: — Take  the  six  ounces  of  fresh  peel  and  beat 
well  with  an  ounce  or  two  of  sugar,  before  adding  the  water  and  spirit 
for  producing  the  tincture  ;  will  it  retain  its  fresh  flavor  quite  un- 
changed ? — Pharm.  Journ.  and  Trans.,  Nov.  16,  1872. 
THE  PRESENCE  OF  SILVER  IN  COMMERCIAL.  SUBNITRATE  OF 
BISMUTH. 
By  Charles  Ekin,  F.  C.  S. 
In  the  June  number,  1868,  of  the  Pharmaceutical  Journal,  will  be 
found  a  short  paper  of  mine  on  "  Commercial  Bismuth,''  in  which  I 
pointed  out  that,  whilst  the  tests  given  in  the  Pharmacopoeia  for  bis- 
muthum  purificatum  excluded  copper,  and  the  process  for  purifying 
it  eliminated  arsenic  and  antimony,  no  notice  was  taken  of  the  prob- 
able presence  of  silver,  notwithstanding  that  it  was  known  that  com- 
mercial bismuth  frequently  contained  silver.* 
My  attention  was  again  called  to  the  matter  by  receiving  the  other 
day  from  a  well-known  and  highly  respectable  firm  of  manufacturing 
-chemists  a  sample  of  subnitrate  of  bismuth,  containing  so  much  sil- 
ver that  when  exposed  to  the  light  it  became  of  a  deep  bluish-black 
tint.  I  obtained  a  sample  from  another  firm  of  at  least  equal  stand- 
ing as  manufacturing  chemists,  and  to  my  surprise  I  found  that  even 
this  too  contained  a  very  appreciable  amount  of  silver.  Upon  this  I 
decided  to  investigate  the  matter  further,  and  obtained  samples  from 
four  of  the  first  dispensing  houses  in  the  country,  for  examination. 
Each  sample  was  dissolved  in  nitric  acid,  diluted  with  an  equal  vol- 
ume of  water,  the  insoluble  residue,  if  any,  was  collected  on  a  filter, 
well  washed  first  with/liluted  nitric  acid,  and  afterwards  with  wrater, 
and  then  treated  on  the  filter  with  ammonia.    The  presence  of  silver 
*See  American  Journal  of  Pharmacy,  1871,  p.  292. 
