AmMJa0rT'i8>7h8arm'}  Liquor  Ferri,  T *eroxy  chloride  of  Iron,  etc.  99 
precipitates  are  obtained,  which  are  also  soluble  in  water,  provided  that 
ammonia  was  not  added  in  excess.  The  more  ammonia  is  used  the 
more  basic  the  precipitates  will  be  ;  these  have  the  advantage  that  the 
ammonium  chloride  can  be  more  perfectly  removed  by  washing  before 
the  precipitates  begin  to  dissolve,  which  is  evidenced  by  the  yellow 
color  of  the  filtrate,  so  that  they  may  be  washed  until  the  filtrate 
becomes  merely  opalescent  on  addition  of  silver  nitrate,  or  keeps  per- 
fectly clear.  It  is  of  the  greatest  importance  that  these  more  basic 
precipitates  be  as  free  as  possible  from  ammonium  chloride,  since  a 
small  quantity  prevents  their  solution.  (It  is  the  presence  of  ammo- 
nium chloride,  also,  that  causes  the  gelatinization  of  solutions  of  the 
less  basic  oxychlorides.) 
These  more  basic  precipitates  do  not  form  a  jelly  after  being  thor- 
oughly washed,  but  finally  form  a  thick  blackish  syrupy  liquid,  which 
when  taken  from  the  filter  gives,  on  addition  of  a  little  water,  a  very 
turbid  mixture,  and,  on  standing  several  days,  a  thin  clear  liquid,  of  a 
brownish-black  color,  or  they  only  change  their  color  by  washing  to  a 
somewhat  darker  but  not  black  hue,  without  losing  much  of  their 
bulkiness.  This  is  the  case  with  the  precipitates  that  were  removed 
from  a  neutral  supernatant  liquid.  After  they  are  washed  until  the 
filtrate  remains  clear  on  addition  of  silver  nitrate,  the  precipitates  are 
taken  from  the  filter  and  transferred  with  a  little  water  into  bottles,  so 
that  they  can  be  shaken  from  time  to  time.  The  color  of  the  mixture 
is  then  reddish-yellow  or  reddish-brown,  but  darkens  from  day  to  day 
as  the  precipitate  enters  solution.  In  the  course  of  several  weeks  a 
clear  thin  liquid,  of  brown  color,  is  obtained.  A  temperature  of  8o° 
to  85°F.  accelerates  the  solution  of  the  precipitates,  while  a  much 
higher  temperature  prevents  it. 
A  few  experiments  were  made  by  adding  to  the  precipitates,  in  per- 
fectly neutral  liquids,  respectively  one-half  and  one  per  cent,  of  the 
ferric  solution.  Under  frequent  stirring  the  mixture  was  allowed  to 
stand  for  two  days,  after  which  the  washing  was  commenced,  and  con- 
cluded finally  on  a  filter,  as  above  mentioned. 
The  writer  gives  below  the  results  of  the  analyses  of  different  prep- 
arations obtained  by  the  above-explained  methods,  the  analyses  being 
made  as  follows  : 
The  solutions  were  thoroughly  mixed  with  an  excess  of  pure  sodium 
carbonate  and  evaporated  to  dryness.    After  dissolving  the  excess  of 
