ON  ACIDUM  HYDRIODICUM  DILUTUM. 
41 
of  potassa  is  clearly  an  advantage,  as  in  nearly  every  case  it 
partially  removes  the  objectionable  odor,  and  in  quite  a  number 
of  instances  gives  an  alcohol  clean  enough  for  very  many  pharma- 
ceutical purposes.  None  of  the  experiments  made  by  the  writer 
gave  anything  like  a  fine  deodorized  alcohol  suitable  for  use  in 
perfumery  or  for  delicate  preparations,  nor  does  he  think  that 
such  an  alcohol  can  be  produced  on  the  small  scale,  with  the 
apparatus  at  the  command  of  the  pharmacist,  and  our  present 
knowledge  of  the  subject. 
The  reaction  of  permanganates  with  organic  matter  is  due  to 
the  decomposition  of  the  permanganic  acid  (Mn20y),  which  is 
resolved  into  hydrated  binoxide  of  manganese,  and  oxygen, — 
Mug  O7  =  2  (Mn  O2)  +  3  0.  The  oxygen  being  in  a  nascent 
state,  instantly  combines  with  the  organic  matters  present  and 
destroys  them.  In  the  case  of  unclean  alcohol,  the  permanganic 
acid  seems  first  to  destroy  the  odorous  principles  present,  and,  if 
in  sufficient  excess,  to  then  destroy  the  alcohol. — Proc.  Amer. 
Pharm.  Assoc,  1868.. 
ON  ACIDUM  HYDRIODICUM  DILUTUM. 
By  John  A.  Dunn. 
Query  2d. — Is  the  officinal  process  for  Acidum  Hydriodicum  the  best 
that  can  be  practically  suggested  ? 
The  officinal  process,  when  managed  with  skill,  yields  a  good 
product,  but  in  practice,  besides  being  very  troublesome,  it  has 
at  least  one  great  objection,  and  that  is  the  use  of  sulphuretted 
hydrogen  in  its  preparation.  The  dispensing  pharmacist  does 
not  want  to  contaminate  the  atmosphere  of  his  store  with  this 
odor  if  it  can  be  avoided.  In  order  to  avoid  this,  and  simplify 
the  process,  the  writer  determined  to  make  some  experiments 
with  Buchanan's  method,  hoping  by  some  slight  modification  to 
obtain  a  good  and  reliable  product,  and  one  that  would  represent 
that  of  the  U.  S.  Pharmacopoeia  in  the  proportion  of  iodine. 
The  chief  objection  to  Buchanan's  process,  in  the  original  form, 
is  that  it  invariably  deposits  crystals  of  bitartrate  of  potassa  on 
standing ;  this  the  writer  believes  he  has  obviated,  at  least  to  a 
practically  useful  extent,  and  as  the  results  of  his  experiments 
in  that  direction,  offers  the  following  modified  process : 
