Am,i°ayr;iSarm'}     Commercial  Hypophosphorous  Acid.  245 
D  was  a  sample  kindly  furnished  me  by  a  retail  pharmacist  in 
town.  The  time  at  my  disposal  would  not  admit  of  an  examination 
of  more,  but  I  believe  the  above  are  typical  of  the  commercial  article. 
The  tests  to  which  each  sample  was  subjected,  were ; 
1st.  A  solution  of  calcic  acetate  containing  excess  of  acetic  acid  to 
detect  oxalic  acid  or  other  oxalates. 
2nd.  A  solution  of  ammonium  oxalate  to  detect  calcium  salts. 
3rd.  A  solution  of  plumbic  acetate  containing  excess  of  acetic  acid 
to  detect  phosphorous  acid,  or  other  phosphites. 
I  relied  on  the  last  test,  from  the  fact  stated  in  Watts'  "  Dictionary 
of  Chemistry/'  that  phosphite  of  lead  is  insoluble  in  acetic  acid. 
As  these  were  likely  impurities  from  the  known  methods  of  prepa- 
ration, more  attention  was  devoted  to  them  than  others. 
In  making  qualitative  estimations,  the  modus  operandi  consisted  in 
adding  to  a  small  quantity  of  the  sample  the  calcic  acetate  solution. 
In  none  of  them  was  there  an  immediate  precipitate,  but  on  gently 
heating,  or  by  merely  stirring,  a  characteristic  one  began  to  appear  in 
every  sample  more  or  less  abundantly. 
The  ammonium  oxalate  reagent  at  once  produced  a  precipitate  in 
them  all,  and,  as  this  seemed  to  indicate  that  the  oxalic  radicle  was 
contained  as  calcium  salt  dissolved  by  the  acid,  each  solution  was 
neutralized  by  AmHO,  and  filtered  from  the  precipitate,  whkh 
formed  in  every  case,  care  being  taken  to  use  a  sufficiently  diluted 
solution.  The  precipitate  was  examined,  and  found  to  consist  of  cal- 
cium oxalate  in  every  case. 
The  filtrate  was  tested  for  the  oxalic  radicle  in  the  usual  way,  and 
for  calciiun. 
The  oxalic  radicle  being  absent,  the  filtrate  was  tested  after  an  ex- 
cess of  acetic  acid  had  been  added  by  the  acetate  of  lead  reagent. 
Of  other  impurities  there  were  none  likely  and  none  found  in 
sufficient  quantity  to  warrant  notice. 
The  results  are  tabulated  below  : — 
Excess  of  Excess  of 
Sample.  CaC204  oxalic  acid.  Ca2PH202  H3P03 
A  .  Abundant  Absent  Abundant  Absent 
B  .  Present  Absent  Present  Trace 
C  .  Present  Absent  Abundant  Absent 
D  .  Present  Absent  Present  Absent 
Comment  or  inference  from  these  will  be  left  over  until  the  quan- 
titative analyses  have  been  stated.    The  specific  gravities  were  taken 
