PROCESS  FOR  PROCURING  PHOSPHORUS. 
551 
NEW  PROCESS  FOR  PROCURING  PHOSPHORUS. 
By  M.  Cari-Montrand. 
M.  Dumas  read  to  the  Academy  of  Sciences,  at  Paris,  at  their* 
Session  of  15th  May,  a  letter  from  a  young_chemist,  M.  Cari-Mon- 
trand,  in  which  he  proposes  a  new  mode  for  the  preparation  of 
phosphorus  on  a  practical  scale,  the  usual  process  being  slow, 
complicated,  yielding  but  little  product,  and  giving  an  educt  of 
no  value.  The  process  proposed  consists  of  passing  over  a  thorough 
mixture  of  equal  parts  of  finely-powdered  charcoal  and  bone-earth, 
at  a  red  heat,  a  quantity  of  dry  hydro-chloric  acid,  or  still  better, 
of  dry  chlorine.  The  end  of  the  porcelain  tube  in  which  the  ex- 
periment was  performed,  was  attached  to  a  glass  tube  dipped  un- 
der water.  Phosphorus,  carbonic  oxide,  and  water,  are  given  off, 
and  chloride  of  calcium  is  left  in  the  tube.  On  analysis,  no  trace 
of  phosphoric  acid,  or  any  other  compound,  was  found  in  the  tube  ; 
the  decomposition  is  therefore  complete,  and  as  no  phosphorus 
passed  off,  the  whole  amount  contained  in  the  earth  was  obtained 
as  a  product.  The  following  equation  explains  the  reaction,  when 
hydro-chloric  acid  is  used  : 
3Ca.O,  P05  +  5C  +  3HC1.  =  5  CO -f  3HO+3Ca.  CI.  -J-  P. 
The  same  letter  contains  a  notice  interesting  to  chemists,  of  the 
entire  decomposition  of  gypsum,  and  the  procuring  of  its  sulphu- 
ric acid,  by  treatment  of  a  mixture  with  charcoal  by  dry  chlorine, 
or  hydro-chloric  acid  gas.  A  good  deal  of  excitement  appears  to 
have  been  caused  among  some  of  the  would-be  scientific  papers, 
by  the  announcement  of  this  process,  which,  it  was  asserted,  would 
materially  reduce  the  price  of  sulphuric  acid.  But  it  will  be 
easily  seen  that,  at  least  the  equivalent  of  hydro-chloric  acid  (dry 
weight  36),  must  be  used  for  each  equivalent  of  oil  of  vitriol, 
(weight  49,)  the  process  would  be  more  expensive  than  at  present. 
This  is  clearly  stated  by  M.  Cari-Montrand,  who  had  the  process 
tried  on  a  large  scale  by  M.  Kuhlmann,  but  found  that  the  expense 
of  making  and  drying  the  hydro-chloric  acid,  was  an  insurmount- 
able obstacle  to  its  introduction  into  the  arts. — Journal  of  the 
Franklin  Institute,  Sept.,  1854. 
