PROCESS  FOR  PREPARINa  JAMES'  POWDER.  535 
twenty  grains  at  once,  without  much  elBfect  on  the  stomach, 
bowels,  or  skin. 
There  is  a  slight  objection  to  conducting  the  process  of  roast- 
ing in  an  iron  ladle,  and  raking  with  an  iron  rake  ;  minute  par- 
ticles of  protoxide  of  iron  are  found  in  the  resulting  powder, 
very  small  in  quantity,  but  unpleasant  in  appearance.  This 
may  be  remedied  by  substituting  an  earthen  dish,  and  it  was 
such  a  vessel  that  Pearson  used  in  his  experiments  ;  but  the  iron 
ladle  is  far  more  convenient. 
I  believe  that  James's  powder  may  be  prepared  in  the  follow- 
ing manner  : — Let  any  quantity,  say  eight  ounces,  of  bone- 
shavings  be  heated  in  an  earthenware  dish  or  an  iron  ladle  over 
a  moderate  fire,  and  frequently  stirred  or  raked  during  its  in- 
cineration. When  burnt  to  a  black  powder  and  ammoniacal 
fumes  are  no  longer  perceptible,  let  four  ounces  of  levigated  sul- 
phuret  of  antimony  be  thrown  in,  and  let  stirring  with  an  iron 
rod  from  the  bottom  and  all  parts  be  immediately  commenced 
and  rapidly  continued,  so  that  the  sulphureous  fumes  shall  have 
a  free  issue  and  be  no  longer  discoverable.  This  is  most  im- 
portant. 
During  the  desulphuration  the  heat  should  be  kept  as  low  as 
may  be  sufficient  to  cause  the  discharge  of  the  vapor.  In  the 
dark,  the  powder  should  show  a  thin,  blue  flame,  as  faint  as  pos- 
sible ;  but  as  often  as  this  flame  disappears,  the  heat  should  be 
gently  raised  until  it  again  appear.  But  neither  the  bottom  of 
the  ladle  nor  the  powder  should  be  allowed  to  become  red-hot 
while  vapors  are  discharged,  or  while  there  is  blue  flame  from 
the  burning  sulphur.  At  length  even  a  higher  heat  will  not 
expel  any  more  sulphur.  During  this  roasting,  innumerable 
bright  spiculae  of  metallic  antimony  will  sparkle  through  the 
powder.  The  ladle  and  its  contents  may  be  allowed  to  become 
red-hot  for  two  or  three  minutes,  the  raking  being  continued. 
If  the  process  has  been  rightly  conducted,  the  powder,  at  this 
stage,  will  have  assumed  the  color  of  the  dust  of  Bath  brick. 
The  contents  of  the  ladle  should  now  be  powdered,  sifted, 
transferred  to  a  skittle-pot,  its  cover  laid  on  and  the  whole 
placed  on  a  stand  in  the  fire-grate,  and  lumps  of  coal  are  to  be 
built  round  and  above  it  in  such  a  way  as  to  permit  a  free 
