HYP0PH0SPH1TES. 
513 
vents,  in  a  great  measure,  the  tendency  to  formation  of  phosphates, 
producing  more  hypophosphites.  At  the  same  time  converting  a 
large  portion  of  the  phosphuretted  hydrogen  into  the  non-inflam- 
mable condition. 
The  result  of  some  experiments  based  on  the  above  reports,  are 
as  follows : 
Phosphorus  was  reduced  to  powder  by  melting  it  under  alcohol, 
in  a  water  bath,  and  agitating  constantly  while  the  bottle  was  cooled 
under  the  hydrant.  The  phosphorus  in  powder  (together  with  the 
alcohol  used,)  was  added  to  a  cold  saturated  solution  of  sulphide  of 
barium,  and  digested  in  the  cold  during  several  days,  stirring  occa- 
sionally. A  small  amount  of  inflammable  phosphuretted  hydrogen 
was  evolved.  The  mixture  was  then  exposed  to  a  temperature  un- 
der 212°,  but  little  more  inflammable  gas  was  given  off,  and  but 
little  smell.  The  heat  was  continued  till  the  liquor  was  no  longer 
alkaline,  and  ceased  almost  entirely  to  darken  paper  wet  with  a 
dilute  solution  of  subacetate  of  lead.  It  was  then  filtered,  digested 
with  carbonate  of  lead,  again  filtered,  and  an  almost  pure  solution 
of  hypophosphite  of  baryta  obtained.  The  baryta  salt,  precipitated 
by  carbonate  of  soda,  yielded  the  soda  salt,  which,  when  dry,  some- 
what exceeded  in  weight  the  amount  of  phosphorus  employed . 
During  the  early  stages  of  the  process,  no  free  sulphuretted  hydro- 
gen was  detected,  but  at  the  close  of  the  operation  lead  paper  was 
darkened  when  held  over  the  vessel  containing  the  baryta  salt. 
The  amount  of  heat  necessary  in  the  operation  was  nearly  of  as 
long  continuance  as  is  required  in  forming  the  lime  salt.  The  pro- 
cess does  not  appear  to  offer  any  advantages  over  the  one  in  general 
use,  except  where  the  object  is  to  obtain  a  pure  acid,  which  is  read- 
ily done  by  precipitating  the  baryta  by  sulphuric  acid. 
Pelouze  and  Fremy  state,  that  hypophosphorous  acid  is  distin- 
guished from  phosphorous  acid  by  the  former  causing  a  precipitate 
of  sulphur  when  added  to  sulphuric  acid,  no  such  reaction  being 
caused  by  phosphorous  acid. 
Philadelphia,  Sept.  1858. 
