130      PHOSPHATE  OF  LIME  IN  SUBNITRATE  OF  BISMUTH. 
ten  minutes,  gave  a  bulky,  insoluble,  basic  precipitate.  I  bave 
also  dissolved  "metallic  bismuth,"  passing  it  through  the  same 
process  ;  and,  whether  boiled  or  otherwise,  the  results  have  been 
the  same  in  each  instance  as  detailed  above. 
I  have  carefully  examined  the  precipitates  formed,  and  pro- 
duced a  considerable  bead  of  metallic  bismuth  before  the  blow- 
pipe, whether  phosphate  of  lime  has  been  added  or  not.  The 
natural  conclusion  to  be  arrived  at  is  this,  that  whilst  the  modi- 
fication suggested  by  Messrs.  Howard  and  Sons  may  serve  as  a 
kind  of  negative  test  in  the  cold,  it  cannot  be  relied  upon  as  an 
absolute  test,  and  especially  not  when  the  solution  is  boiled ; 
although  it  may  serve  to  show  the  presence  of  a  phosphate,  it  is 
open  to  the  same  objection  as  that  suggested  by  Mr.  Roussin. 
I  have  found  in  all  my  experiments  with  this  most  eccentric 
of  metals  that  it  will  not  bear  boiling  in  the  presence  of  free  am- 
monia ;  even  the  Pharmacopoeia  liquor,  and  others  which  have 
come  under  my  notice,  give  this  same  basic  change  when  boiled 
with  this  agent  in  excess. 
There  is  a  question  growing  out  of  this  well  worthy  the  care- 
ful examination  of  experimenters,  viz.,  does  the  salt  of  bismuth 
undergo  a  change  when  boiled*  in  the  presence  of  phosphate  of 
lime  and  nitric  and  citric  acids,  producing  an  insoluble  phosphate 
of  bismuth  ?  Phosphate  of  bismuth  we  know  is  not  soluble  in 
acetic  acid,  but  freely  so  in  dilute  hydrochloric  acid.  These 
precipitates  produced  by  the  above-enumerated  process  corres- 
pond to  this ;  but  I  have  had  no  time  to  pursue  them  further, 
and  should  be  glad  to  see  the  subject  investigated  by  more  able 
hands. 
This  subject  is  an  important  one,  from  the  fact  that  manufac- 
turers and  wholesale  houses  may  be  exposed  to  unjust  imputa- 
tions, through  hasty  experimenters  calling  the  precipitate  pro- 
duced by  Mr.  Roussin's  and  Messrs.  Howard's  test  phosphate  of 
lime,  and  estimating  the  percentage  as  such,  when  none  exists 
in  the  salt.  And  the  more  especially  is  it  important  that  great 
care  should  be  exercised,  as  it  appears  that  this  adulteration  is 
one  of  foreign  origin,  and  the  possession  of  drugs  thus  adulterated 
renders  the  possessor  liable  to  a  heavy  penalty. 
It  would  not,  therefore,  be  policy  for  any  one  to  rely  upon  a 
