ST2 
kochleder's  proximate  analysis. 
the  taste  of  the  original  liquid.  When  the  quantity  of  fluid  set  apart  for 
the  experiment  has  run  through  the  charcoal,  and  this  fluid  has  been  re- 
moved, the  charcoal  is  washed  with  cold  water,  to  completely  separate 
the  bodies  which  are  not  retained  by  the  charcoal.  The  charcoal  is  trans- 
ferred to  a  vessel  suitable  for  boiling,  and  boiled  with  strong  alcohol.  The 
spirit  is  filtered  hot  from  the  charcoal  by  means  of  a  hot-water  funnel, 
and  the  decoction  with  alcohol  repeated  as  long  as  this  takes  up  anything. 
The  spirituous  solutions  are  concentrated  by  distilling  off  the  greatest  part  of 
the  alcohol,  and  the  concentrated  extract  (the  residue  of  the  distillation) 
is  allowed  to  stand,  to  ascertain  whether  crystals  form  or  not  therein. 
Should  crystals  not  separate  by  long  standing,  the  residue  is  dissolved  in 
water  and  further  examined.  On  the  contrary,  should  crystals  form,  they 
are  first  separated  from  the  mother  liquor,  and  these,  as  well  as  the  mother 
liquor,  subjected  to  a  closer  examination.  The  liquid  treated  with  animal 
eharcoal  is  treated  precisely  as  the  first  portion  of  watery  decoction. 
A  third  j)ortion  of  the  watery  decoction  is  mixed  with  a  solution  of  alum, 
and  then  ammonia  is  added  to  the  fluid.  If  a  ijrecipitate  results  thereby, 
the  alumina  exists  therein,  partly  as  a  hydrate,  partly  combined  with  one 
or  more  organic  substances.  The  precipitate  is  removed  by  filtration,  and 
washed  on  the  filter  with  water.  To  the  filtrate  so  much  dilute  sulphuric 
acid  is  added  as  will  almost  neutralize  the  whole  quantity  of  free  ammo- 
nia which  has  been  added  in  excess.  The  residue  of  ammonia  is  satu- 
urated  with  a  few  drops  of  acetic  acid,  the  neutralized  fluid  is  evaporated 
to  a  small  volume,  and  the  residue  mixed  with  anhydrous  alcohol.  This 
precipitates  a  considerable  quantity  of  sulphates  of  potash  and  ammonia, 
which  should  be  removed  from  the  alcoholic  solution  by  filtration.  From 
this  solution  the  alcohol  is  distilled  off,  and  the  syrupy  residue  again 
treated  with  hot  anhydrous  alcohol,  which  separates  the  rest  of  the  sulphates, 
sometimes  mixed  with  more  or  less  organic  matter  insoluble  in  alcohol. 
This  alcoholic  solution  is  likewise  freed  from  the  greatest  part  of  its  alco- 
hol by  distillation,  and  the  residue  set  aside,  by  which  crystals  are  fre- 
quently separated  ;  the  crystals  and  the  mother  liquor  are  separated,  and 
submitted  to  a  closer  investigation.  When  no  crystals  are  formed,  the 
whole  residue  is  subjected  to  investigation. 
We  return  now  to  both  the  jyrecipitates  which  were  produced  by  sugar  of 
lead  and  suhacetate  of  lead  in  the  first  part  of  the  aqueous  decoction.  As  before 
remarked,  the  second  part  of  the  watery  decoction,  after  treatment  with 
animal  charcoal,  is  precipitated  with  sugar  of  lead  and  subacetate  of  lead  ex- 
actly in  the  same  way  as  the  first  part  of  the  watery  decoction  not  treated 
with  animal  charcoal.  If  the  animal  charcoal  has  not  taken  up  and  re- 
tained any  substances  from  the  watery  solution,  it  is  self  evident  that  the 
precipitates  obtained  by  sugar  of  lead  and  subacetate  of  lead  in  the  portion 
of  the  watery  decoction  treated  with  animal  charcoal,  have  quite  the  same 
composition  as  the  corresponding  precipitates  from  the  first  part  of  the 
decoction  which  was  not  treated  with  animal  charcoal.    In  this  case,  the 
