450 
PERMANGANATE  OF  POTASH. 
employed  crude  opium,  laudanum,  decoction  of  nux  vomica  and  of 
false  angustura  bark  ;  and  in  these  cases  also,  he  was  able  to  isolate 
the  poisonous  principles.  He  also,  in  order  to  assure  himself  that 
his  process  was  applicable  to  medico-legal  purposes,  poisoned  ani- 
mals with  the  smallest  effective  doses  of  the  above-mentioned 
substances,  when  he  was  able  to  detect  the  poisons  in  the  matters 
contained  in  the  stomach  and  intestines,  and  sometimes  even  in 
organs  to  which  they  had  been  carried  by  absorption. 
In  one  experiment,  he  mixed  2  grs.  (or  10  centigrms.)  of  mor- 
phine with  100  grms.  of  flesh,  leaving  the  substances  to  undergo 
putrefaction  for  two  months.  At  the  end  of  this  period  he  disco- 
vered several  centigrammes  of  morphine  in  the  mass. — Chemical 
Gazette,  from  Comptes  Rendus,  March  21,  1853. 
PERMANGANATE  OF  POTASH. 
In  consequence  of  the  successful  use  of  permanganate  of  potash 
in  diabetes,  under  Mr.  Sampson,  the  results  of  which  have  been 
lately  published  in  the  Lancet,  and  as  it  is  probable  that  it  will 
come  into  more  general  use,  we  think  a  short,  notice  of  it  will  be 
found  useful  to  our  readers. 
This  salt  is  formed  by  the  mixture  of  peroxide  of  manganese 
with  hydrate  of  potash;  the  resulting  salt  is,  however,  more  abun- 
dant, if  chlorate  of  potash  be  used  in  addition. 
There  are  several  modifications  of  the  process:  that  of  Chevillot 
and  Edwards  is  to  ignite  one  part  of  peroxide  of  manganese  with 
one  part  of  hydrate  of  potash, dissolve  the  resulting  mass  in  water, 
decant  the  red  solution  and  evaporate,  rapidly  at  first,  till  small 
needles  appear,  then  cautiously,  that  crystallization  may  go  on 
regularly.  Wohler's  (Pogg.  xxvii.,  626)  process  is  as  follows : 
chlorate  of  potash  being  kept  in  a  state  of  fusion  over  a  spirit 
lamp,  hydrate  of  potash  is  first  added  to  it,  and  then  an  excess  of 
finely  divided  peroxide  of  manganese,  which  immediately  dissolves, 
forming  a  splendid  green  solution.  The  mixture  is  then  heated  till 
the  whole  of  the  chlorate  of  potash  is  decomposed,  and  the  mass 
when  cold  is  boiled  with  a  small  quantity  of  water,  whereupon  the 
green  color  of  the  solution  changes  to  red  ;  finally,  the  liquid  is 
decanted  from  the  peroxide  of  manganese  while  still  hot,  and  set 
aside  to  crystallize  by  cooling.    It  crystallizes  in  all  proportions 
