Am.  Jour.  Pharm. 
Feb.,  1888. 
Mermrammonium  Chlorides. 
81 
parts  of  mercuric  and  ammonium  chlorides,  by  addition  of  sodium - 
carbonate.  Nothing  is  stated  regarding  the  action  of  water  upon  this 
compound. 
Dimercurammonium  chloride  hydrated,  NHggCl.HgO  is  theoreti- 
cally gotten  by  the  introduction  of  two  dyad  mercury  atoms  in  place 
of  four  hydrogen  atoms  in  a  single  molecule  of  ammonium  chloride. 
It  is  described  as  a  yellowish  or  a  yellow  granular  compound,  conver- 
tible into  a  white  powder  by  a  solution  of  ammonium  chloride,  and  is 
obtained  by  boiling  the  mercurammonium  chloride  with  a  large  excess 
of  water.  If  this  is  boiled  with  potassium  hydrate,  it  is  converted 
into  dimercurammonium  hydroxide  while  potassium  chloride  is 
formed :  NHg^Cl+KOH^NHgPH+KCl. 
With  a  view  of  studying  more  especially  the  first  two  compounds  as  to 
the  best  methods  of  commercial  preparation,  the  action  of  heat  upon 
them  as  applied  to  the  precipitation  from  cold  and  boiling  solutions, 
if  possible,  to  devise  a  test  by  which  they  could  be  easily  distinguished, 
and  lastly,  a  ready  method  of  analysis,  a  series  of  experiments  were 
made. 
A  number  of  specimens  were  made,  and  these,  after  analysis,  can  be 
divided  into  four  classes  : 
I.  Formula  NH2HgCl. 
II.  Mixtures  of  NH^HgCl  and  (NH3Cl)2Hg. 
III.  Formula  NHgaCl.HsO. 
IV.  Formula  NHg^Cl. 
All  of  the  specimens  under  I.  and  II.  were  washed,  after  placing 
them  in  small  percolators,  with  2  portions  of  dilute  ammonia  water 
(1-20)  of  20  cc.  each  :  after  draining  they  were  pressed  between  sheets 
of  filter-paper  to  remove  excessive  moisture,  and  dried  in  an  oven  at  a 
temperature  between  30°  and  40  °C. 
Specimens  under  III.  and  lY.  being  decomposition  products,  were 
simply  washed  with  water  and  dried  as  above. 
I.  a  Made  by  the  U.  S.  P.  process. 
I.  b  By  boiling  for  thirty  minutes,  after  adding  the  ammonium 
hydrate  in  excess  to  solution  of  mercuric  chloride. 
II.  As  the  compounds  NHaHgCl  and  (NH3Cl)2Hg  differ  by  one 
molecule  of  ammonium  chloride,  it  was  considered  possible  to  form 
the  latter  by  precipitating  mercuric-chloride  solution,  in  presence  of 
excess  of  ammonium  chloride,  by  ammonium  hydrate. 
The  filtrate  obtained  in  the  preparation  of  the  specimens  under  II. 
