Am.  Jour.  Pharm. ) 
August,  1883.  j 
Tinctura  Ferri  Chloridi. 
391 
A  specimen  each  of  the  alcoholic  and  aqueous  solutions  was  exposed 
to  the  action  of  sunlight  and  air.  On  examination  it  was  seen  that 
the  reducing  action  of  the  alcohol  overcame,  to  a  considerable  extent, 
the  oxidizing  action  of  the  air,  as  will  be  seen  by  the  following  table. 
No.  cc. 
KaMnaOg 
used. 
Amount  of 
ferrous  iron 
present. 
Amount  of 
ferric  iron 
present. 
Per  cent,  of 
ferrous  iron. 
Alcoholic  tincture  exposed  to  sun 
32-5 
•174528 
•099370 
63-5154 
The  aqueous  solution  was  not  affected  in  the  least. 
The  theoretical  amount  and  percentage  of  iron,  etc.,  of  the  officinal 
solution  and  tincture  is  shown  in  the  appended  table : 
Amount  of 
iron. 
Per  cent,  of 
iron. 
Per  cent,  of 
FeaCle. 
Per  cent. 
of 
Fe2Cl6.12K20. 
-2604 
•22820 
13-02 
4-564 
37-6878 
13-2308 
68-8211 
22-015 
The  estimations  of  the  percentage  strength  of  the  officinal  prepara- 
tions were  made  from  the  gravimetric  test  of  the  Pharmacopoeia,  the 
accuracy  of  which  has  been  shown  to  be  doubtful.  The  percentage  of 
anhydrous  ferric  chloride  stated  in  the  Pharmacopoeia  description  of 
Liq.  ferri  chloridi  is  37'8.  As  seen  by  the  foregoing  tables,  the  phar- 
macopoeial  solution  and  tincture  contain  less  iron  and  iron  salts  than 
the  commercial  preparations,  and  also  the  preparations  made  for  these 
experiments,  although  the  pharmacopoeial  preparations  are  said  to  be 
of  higher  specific  gravities. 
Dr.  Attfield  strongly  advocates  the  discarding  of  the  alcohol  in  the 
tincture.  He  holds  that  it  is  unnecessary,  expensive,  and  positively 
injurious.  The  only  advantage  claimed  for  its  use  is  that  it  reacts 
with  free  acid  to  form  chloric  ether,  which  is  believed,  by  some  prac- 
titioners, to  be  of  medicinal  advantage  If  chloric  ether  is  desired, 
why  not  dissolve  a  specified  amount  in  alcohol  and,  when  so  desired, 
add  it  to  the  aqueous  tincture,  which  is  not  altered  by  light  and  air? 
In  this  way  an  expensive  ingredient  would  be  dispensed  with  and  a 
known  amount  of  ether  obtained. 
