ON  HYPOPHOSPHITE  OF  LIME. 
223 
tion  will  have  found  it  a  tedious,  troublesome  and  disagreeable 
process,  wherefore  I  have  made  several  experiments,  to  make  it 
in  another  way,  in  which  at  last  I  succeeded. 
According  to  Paul  Thenard,  oxide  of  phosphorus,  when  heated 
with  milk  of  lime,  gives  hypophosphite  of  lime,  and  not  self-in- 
flammable phosphoretted  hydrogen.  This  gave  me  the  idea  to  the 
following  way : 
I  took  phosphorus,  melted  it  under  water,  and  passed  atmos- 
pheric air  into  it,  from  a  gasometer.  The  phosphorus  will  burn 
under  the  water,  and  soon  begins  to  swell  up.  I  continued  to 
let  atmospheric  air  go  to  it,  until  I  hardly  could  see  any  more  fire 
under  the  water,  and  then  let  it  cool.  When  taken  out  of  the 
water,  the  phosphorus  has  a  spongy  appearance  of  at  least  four 
times  its  original  volume,  does  not  so  easily  ignite,  and  at  a 
medium  temperature  it  can  be  left  in  the  air  without  there  being 
any  danger  of  fire.  I  cut  this  so  prepared  phosphorus,  which 
I  consider  a  mixture  of  phosphorus  with  oxide  of  phosphorus, 
into  pieces,  and  put  it  into  milk  of  lime,  which  I  made  by  slack- 
ing lime  with  six  times  its  weight  of  water.  In  a  one  gallon  pot 
I  put  eight  ounces  phosphorus,  twelve  ounces  lime,  and  seventy- 
two  ounces  of  water.  The  action  of  the  lime  on  the  phosphorus 
soon  commences  by  evolving  gas  bubbles,  takes  place  at  any 
temperature,  even  at  the  freezing  point,  but  acts  the  quickest  at 
about  130°  F.  The  gas  bubbles  consist  mostly  of  hydrogen  and 
not  self-inflammable  phosphoretted  hydrogen ;  but  now  and  then 
some  bubbles  rise  which  explode  in  the  air. 
This  method  has  the  advantage,  that  it  yields  more  than  the 
boiling  process,  which  I  think  is  owing  to  the  lower  temperature 
at  which  the  reaction  takes  place.  Out  of  two  ounces  of  phos- 
phorus, with  which  I  first  experimented,  I  got  two  and  a  half 
ounces  of  hypophosphite  of  lime,  and  yet  not  all  the  phosphorus 
was  dissolved.  I  am  sure  that  by  bringing  the  process  to  an 
end,  one  part  of  phosphorus  will  give  one  and  a  half  part  of 
hypophosphite  of  lime.  Do  I  want  to  get  some  hypophosphite 
before  the  process  is  ended,  I  just  let  the  phosphorus  with  the 
lime  settle,  take  off  the  liquid  with  a  siphon,  and  replace  it  with 
water,  and  the  formation  of  hypophosphite  will  continue. 
Another  advantage  is,  that  very  little  iuflammable  phospho- 
retted hydrogen  is  formed,  and  that  the  smell  is  not  so  offensive ; 
