2 1  (J*  Tinctura  Ferri  Chloridi.  {A\llyjj6arm' 
being  taken  to  follow  out  minutely  the  "  Pharmacopoeia  "  directions  as 
to  temperature,  &c.  The  result  convinced  me  that  the  effect  of  light 
on  the  preparation  has  little  or  nothing  to  do  with  the  chemical  change 
resulting  in  the  discoloration  so  often  seen  in  this  syrup,  but  is  the 
result  of  atmospheric  change  in  the  bottle,  caused  by  careless  stopping 
or  defective  corks. 
From  the  syrup  six  one-ounce  vials  were  filled  ;  three  of  these  were 
corked  ;  three  were  glass-stoppered  vials,  in  one  of  which  the  stopper 
was  coated  with  paraffin.  The  syrup  in  two  of  the  corked  bottles 
retained  the  desired  appearance.  The  portion  in  the  glass-stoppered 
vials  met  with  a  change  in  one  instance ;  the  stopper  coated  with  paraf- 
fin and  another  fitting  securely,  remaining  unchanged.  These  bottles 
were  all  placed  in  a  window,  exposed  during  the  greater  part  of  the 
day  more  or  less  directly  to  the  sun's  rays,  remaining  in  this  state  for 
about  one  month. 
I  have  found  that  the  addition  of  either  phosphoric  or  citric  acid,  as 
suggested  by  Mr.  Thos.  B.  Groves  ("Am.  Jour.  Pilar.,"  1868,  page 
265),  to  be  of  great  benefit  in  preserving  the  syrup  from  atmospheric 
action,  resulting  in  altered  properties  and  unsightly  appearance. 
Philadelphia,  March  25,  1876. 
Note  by  the  Editor. — That  the  discoloration  of  syrup  of  ferrous 
iodide  is  due  to  the  oxidizing  influence  of  the  atmosphere,  and  not  to 
light,  has  been  repeatedly  discussed  in  this  Journal  since  1854. 
TINCTURA  FERRI  CHLORIDI. 
BY  ISAAC  R.  DILLER,  PH.G. 
[From  an  Inaugural  Fssay.) 
The  specific  gravity  of  this  tincture  is  '990,  and  each  fluidounce 
should  yield,  when  treated  with  ammonia  water  in  excess,  precipitate  of 
ferric  oxide,  weighing,  after  washing,  drying  and  igniting,  28*8  grains. 
Each  fluidounce  should  also  contain  39*5  grains  of  anhydrous  hydro- 
chloric acid.  It  should  give  no  dark  coloration  on  addition  of  a  crystal 
of  ferrous  sulphate  and  sulphuric  acid  (absence  of  nitric  acid),  and  no 
blue  precipitate  with  potassic  ferridcyanide  (absence  of  ferrous  salt) 
To  see  how  near  the  tinctures  kept  in  the  shops  might  coincide  with 
these  figures  in  regard  to  amount  of  ferric  oxide  and  anhydrous  acid 
contained  in  them,  and  also  their  action  with  the  officinal  tests  given 
