ON  PERMANGANATE  OF  POTASSA. 
547 
ON  PERMANGANATE  OF  POTASSA. 
By  B,  Howard  Rand,  M.D., 
Professor  of  Chemistry  in  Jeiferson  Medical  College. 
This  compound  having  become  a  popular  new  remedy"  with 
many  practitioners,  and  having  undoubtedly  valuable  as  well  as 
dangerous  properties,  I  propose  to  discuss  these  in  a  few  words. 
The  chemical  nature  of  the  salt  need  not  be  dwelt  upon.  Its 
method  of  preparation,  with  the  chemical  changes  involved,  will 
be  found  in  the  United  States  Dispensatory.  It  is  enough  to 
say  that  it  is,  perhaps,  next  to  chromic  acid  or  chloro-chromic  acid, 
the  most  active  oxidizing  agent  known.  In  contact  with  reduc- 
ing agents  or  organic  matter,  it  is  instantly  decomposed,  becom- 
ing reduced  to  black  oxide  of  manganese  and  caustic  potassa. 
The  oxygen  given  off  appears  to  be,  in  great  part,  in  the  form 
of  ozone,  and  rapidly  attacks  and  burns  up  all  varieties  of  or- 
ganic matter,  although  some  resist  longer  than  others. 
In  consequence  of  this  power  of  oxidation,  it  has  been  largely 
employed  externally  as  a  detergent  and  deodorizer,  and  inter- 
nally in  diseases  in  which  an  oxidizing  agent  is  supposed  to  be 
indicated. 
As  to  its  value  where  used  internally  there  is  abundant  testi- 
mony, yet,  I  fear,  but  little  evidence.  The  enthusiasm  with 
which  a  new  remedy  is  employed  by  the  practitioner  seems  to 
give  faith  to  the  patient,  and  "cures"  follow  which  are  properly 
recoveries.  The  same  is  true  of  secret  remedies,  which,  however 
apparently  successful,  are  generally  abandoned  when  their  true 
nature  becomes  known. 
From  its  caustic  character,  permanganate  of  potassa  is  neces- 
sarily used  internally  in  small  doses, — that  is,  about  half  a  grain. 
One  grain  of  the  salt  is  supposed  by  the  chemist  to  be  decom- 
posed by  five  grains  of  ordinary  organic  matter,  or  half  a  grain 
by  two  and  a  half  grains  of  the  same.  Suppose  the  perman- 
ganate to  be  given  in  solution  in  distilled  water,  the  mixture 
made  in  absolutely  clean  vessels  and  dispensed  from  the  same, 
— conditions  very  rarely  fulfilled  in  practice, — we  have  the 
chance  of  its  not  meeting  with  two  and  a  half  grains  of  organic 
matter  in  its  passage  to  the  stomach.    Then,  considering  the 
