180  Preparations  of  Phosphates  of  Iron,  etc.  {AmAJp°r^8grm 
4  successive  portions  of  chloroform  until  all  the  alkaloids  were 
removed.  The  combined  chloroform  solutions  were  allowed  to 
evaporate,  and  the  residue  dried  at  ioo°  C.  for  one  hour,  and 
weighed  as  total  akaloids. 
A  portion  of  this  alkaloidal  residue  indicated  quinine  by  the 
fluorescence  of  the  acid  solution,  the  thalleioquin  reaction,  and  the 
formation  of  a  precipitate  by  ammonia  water,  soluble  in  excess. 
Strychnine  was  indicated  by  moistening  a  film  of  the  residue  with 
H2S04  and  adding  a  minute  fragment  of  potassium  dichromate  when 
a  fading  purple  color  resulted. 
The  liquid  from  which  the  alkaloids  had  been  removed,  after 
being  heated  to  expel  remaining  chloroform,  was  treated  with  a  little 
ammonium  chloride,  and  ammonium  sulphide  added  in  excess,  the 
bottle  completely  filled,  corked  and  set  aside  until  the  supernatant 
liquid  acquired  a  yellow  color  without  a  tinge  of  green. 
The  precipitate  collected  upon  a  filter  and  washed  with  dilute 
ammonium  sulphide,  with  precautions  against  oxidation,  was  dis- 
solved in  dilute  HC1,  the  solution  heated,  filtered  and  thoroughly 
oxidized  with  small  quantities  of  nitric  acid. 
This  ferric  solution  was  strongly  acidulated  with  hydrochloric 
acid  and  a  little  copper  sulphate  and  potassium  sulphocyanate  added. 
Decinormal  volumetric  solution  of  sodium  hyposulphite  was  now 
run  in  until  the  red  color  of  the  liquid  was  discharged,  a  little  starch 
paste  added  and  the  excess  of  sodium  hyposulphite  determined  by  a 
corresponding  strength  solution  of  iodine. 
The  iron  was  calculated  from  the  amount  of  sodium  hyposulphite 
used. 
The  phosphoric  acid  was  precipitated  as  ammonium  magnesium 
phosphate,  by  adding  magnesia  mixture  to  the  ammoniacal  liquid 
from  which  the  iron  had  been  removed  (the  ammonium  sulphide  not 
interfering) ;  after  the  precipitate  had  thoroughly  separated  it  was 
washed  with  ammoniacal  water  and  dissolved  in  a  small  quantity  of 
acetic  acid  and  sodium  or  potassium  hydrate  added,  allowing  the 
solution  to  remain  slightly  acid. 
After  the  addition  of  a  few  drops  of  cochineal  test  solution,  heat 
was  applied  and  volumetric  solution  of  uranium  acetate  run  into  the 
hot  liquid,  until  a  small  excess  of  uranium  producing  a  green  color 
with  the  cochineal  indicated  the  end  of  the  reaction. 
The  uranium  solution  having  previously  been  standardized  under 
