120 
Bismuth  Oxyiodide. 
Am.  Jour.  Pharm. 
March,  1887. 
gotten  by  carrying  out  parallel  experiments  under  normal  pressure. 
These  sealed  tube  experiments  were  not  made  until  BiOI  had  been 
obtained  by  methods  to  be  described  further  on. 
The  medicinal  virtues  attributed  to  the  oxyiodide  of  bismuth  really 
belong  to  mixtures  of  oxyiodide  and  oxy nitrate,  pure  oxyiodide  of 
bismuth  having  as  yet  not  been  used  in  medicine.  A  formula  is  given 
for  the  preparation  of  Bi0NO3(Bi0I)2,  with  the  advantages  of  the  pro- 
duct. 
Bismuth  subnitrate,  10  gm. 
Potassium  iodide,   4  gm. 
Water,   .       ......  50  cc. 
Boil  for  30  minutes,  filter  and  wash  the  precipitate  until  the  wash- 
ings no  longer  produce  turbidity  with  solution  of  silver  nitrate.  Dry, 
first  by  pressing  between  bibulous  paper,  and  then  at  120°  C. 
The  advantages  of  this  product  are :  First,  the  avoidance  of  free 
acid ;  Second,  its  definite  composition ;  Third,  a  higher  percentage  of 
BiOI  than  is  obtained  by  either  of  the  published  processes. 
A  specimen  is  presented  which  was  made  by  boiling  the  above 
quantities  for  only  a  few  minutes,  the  composition  of  which  is  BiON03 
44*59  per  cent.,  BiOI  55*41  per  cent.,  showing  an  incomplete  change. 
It  may  here  be  stated  that  the  percentage  of  BiONOs,  in  specimens 
gotten  by  the  above  process,  can  be  determined  by  subtracting  66*36 
from  the  percentage  of  Bi203,  multiplying  by  100  and  dividing  by  14*89. 
Having  failed  in  the  above  experiments,  as  far  as  the  preparation  of 
a  pure  oxyiodide  of  bismuth  is  concerned,  attention  was  now  paid  to 
the  action  of  potassium  iodide  on  bismuth  oxycarbonate.  The  two 
salts  can  be  boiled  together  for  a  long  time  without  reaction.  If  to 
the  mixture  acetic  acid  be  added,  effervescence  takes  place,  the  color 
rapidly  changes  to  a  red-brown  and  on  continued  boiling  the  salt  be- 
comes crystalline.  The  compound  in  this  case  is  not  definite  in  com- 
position, from  60  to  80  per  cent,  of  the  oxycarbonate  being  changed 
into  oxyiodide.  If  the  compound  so  gotten  be  thoroughly  washed 
and  then  boiled  a  second  time  with  potassium  iodide  and  acetic  acid, 
effervescence  again  occurs  and  the  color  of  the  precipitate  becomes 
darker  (Spec.  Bl.)  This  on  analysis — by  ignition  67  per  cent.  Bi203 
is  obtained — contains  98  per  cent.  BiOI.  When  this  is  boiled  with 
Kl  and  acetic  acid,  a  product  (Spec.  B2)  is  gotton,  leaving  66*50  per 
cent.  Bi203  on  ignition,  corresponding  to  99*50  per  cent.  BiOI. 
