326  Estimation  of  Hypophosphites.  {Amju™Sarm' 
The  reaction  for  this  production  of  chloroform  from  acetone  seems 
to  be  simply  : 
2C8H60+6CaOCl2=2CCl,H+Ca(C2H302)2+2Ca(OH)2+3CaC]2. 
This  would  demand  one  equivalent  of  chloroform  for  one  of  acetone 
used,  or  206  parts  of  chloroform  by  weight  reckoned  on  the  weight  of 
the  acetone.    In  practice  180  parts  are  usually  obtained,  although  200 
parts  have  actually  been  obtained  at  times. 
The  chloroform  obtained  is  quite  free  from  the  chlorinated  side 
products  which  often  accompany  the  chloroform  made  from  alcohol.  It 
is,  nevertheless,  thoroughly  purified  by  treatment  with  sulphuric  acid 
and  careful  washing,  and  it  is  then  brought  exactly  to  the  U.  S.  Phar- 
macopoeia standard. 
\ 
HYPOPHOSPHOROUS  ACID  AND  THE  OFFICINAL 
HYPOPHOSPHITES. 
By  Frank  X.  Moerk,  Ph.  G. 
Contribution  from  the  Chemical  Laboratory  of  the  Philadelphia  College  of 
Pharmacy. — No.  55. 
I.  METHODS  OF  ESTIMATION. 
In  taking  up  the  above  subjects  for  examination,  the  renown  of 
hypophosphorous  acid  and  its  salts  as  reducing  agents  rendered  it 
very  likely  that  abundant  evidence  of  this  property  would  be  had  in 
finding  the  acid  and  its  salts  changed,  partly  at  least,  into  phosphorous 
acid  and  phosphites,  consequently,  the  determination  of  these  last  bodies 
in  presence  of  the  former  was  of  considerable  importance. 
Looking  over  the  reactions  of  the  two  acids  there  are  to  be  found 
only  three  tests  by  which  hypophosphorous  acid  can  be  distinguished 
from  phosphorous  acid,  and,  possibly,  only  one  by  which  phosphorous 
acid  can  be  distinguished  from  hypophophorous  acid.  Hypophos- 
phites :  1,  heated  with  cupric  sulphate  solution  give  a  precipitate  of 
cuprous  hydride  which,  on  boiling,  is  decomposed  into  metallic  copper 
and  hydrogen1;  2,  with  a  nitric  acid  solution  of  ammonium  molyb- 
date  produce  no  change  until  a  few  drops  of  sulphurous  acid  are 
added,  when  a  beautiful  blue  color  results2;  with  ammonium  tung- 
state,  under  same  conditions,  also  a  blue  color 3 ;  phosphites,  in  pres- 
1  Wurtz  :  Elements  of  Chemistry. 
2  Amer.  Jotjrn.  Phar.,  1889,  129. 
3  Amer.  Journ.  Phar.,  1889,  130. 
