80  Mercurammonium  Chlorides.  {^'^' f^<^' im^^' 
from  this  resin  is  tested  with  Fehling's  solution  for  ghicose,  decided 
evidence  of  it  is  obtained. 
It  is  evident  that  the  bitter  principle  is  a  glucoside,  which,  on  boil- 
ing with  dilute  acid,  decomposes  into  the  resin,  which  is  soluble  in 
alcohol  and  sugar.  Having  more  definitely  determined  the  character 
of  the  bitter  principle  and  exhibited  a  distinct  quantity  of  it  in  crys- 
talline form,  I  hope  soon  to  investigate  its  composition  and  properties 
more  fully. 
MEECURAMMONIUM  CHLORIDES. 
Contribution  from  the  Chemical  Laboratorj^,  Philadelphia  College  of  Pharmacy. 
By  Frank  X.  Moerk,  Ph.G. 
Read  at  the  Pharmaceutical  Meeting,  January  17. 
In  pharmaceutical  and  chemical  text-books  mention  is  made  of 
three  compounds  derivable  from  the  formula  of  ammonium  chloride, 
by  the  introduction  of  dyad  mercury  in  place  of  hydrogen. 
Mercurammonium  chloride  JN'HgHgCl,  the  officinal  Ammbniated 
Mercury,  or  commonly  known  as  "  infusible  white  precipitate,"  is  a 
compound  in  which  an  atom  of  dyad  mercury  replaces  two  hydrogen 
atoms  in  one  molecule  of  ammonium  chloride,  NH^Cl.  This  is  got- 
ten by  the  addition  of  mercuric-chloride  solution  to  an  excess  of  am- 
monium hydrate,  or,  by  adding  the  hydrate,  in  excess,  to  the  mercuric- 
chloride  solution  ;  in  either  case,  the  precipitate  gotten  is  washed  with 
a  limited  quantity  of  water  containing  ammonium  hydrate.  By  pro- 
longed washing,  or  by  boiling  with  water,  this  compound  is  decom- 
posed into  hydrated  dimercurammonium  chloride  and  ammonium 
chloride.     2  NH^HgCl  +H20=]SrHg2Cl.H20+NH,Cl. 
Mercurdiammonium  chloride  (NH3Cl)2Hg,  or  "  fusible  white  precipi- 
tate," is  derived  from  two  molecules  of  ammonium  chloride  by  the 
replacement  of  two  hydrogen  atoms,  one  from  each  molecule,  by  one  atom 
of  dyad  mercury.  It  is  formed  by  the  addition  of  mercuric  chloride 
solution  to  a  boiling  solution  of  ammonium  chloride,  containing  ammoni- 
um hydrate  until  the  precipitate  first  formed  ceases  to  redissolve ;  on  cool- 
ing, the  salt  of  the  above  formula  crystallizes.  This  is  a  method  not 
likely  to  be  followed  by  the  manufacturing  chemist  in  making  ammoni- 
ated  mercury,  on  account  of  the  waste  of  ammonium  salts  and  the  loss  of 
the  mercury  compound,  which  is  soluble  in  ammonium  chloride. 
Another  method  is  the  precipitation  of  a  solution  containing  equal 
