6  ACTIVE  PRINCIPLE  OF  KHUS  TOXICODENDRON. 
dilute  hydrochloric  acid,  and  this  solution  had  the  same  odor 
It  appeared  most  likely,  from  this  experiment,  that  the  odor 
was  entirely  distinct  from  the  alkaline  reaction,  or,  in  other 
words,  that  the  odorous  compound  and  the  alkali  were  two 
different  bodies. 
The  solution  had  still  an  acid  reaction  from  the  excess  of 
hydrochloric  acid  employed  when  the  distillation  was  stopped. 
The  liquid  was  now  evaporated  to  dryness,  in  a  current  of  dry 
air  at  a  temperature  of  about  120°  F.,  and  yielded  a  consider- 
able amount  of  a  crystalline  residue,  to  which  the  same  odor 
still  adhered  to  a  certain  degree.  This  crystalline  mass  now 
must  contain  the  volatile  alkaloid  of  Dr.  Khittel. 
A  portion  of  it  was  dissolved  in  distilled  water ;  the  reaction 
of  the  solution  was  neutral  to  litmus  paper.  Tested  with  Son- 
nenschein's  phospho-molybdic  acid,  a  light-yellow  precipitate 
was  obtained,  which  yielded  with  potassa  the  odor  of  ammonia 
only ;  with  Mayer's  iodo-hydrargyrate  of  potassium  in  acidu- 
lated solution,  no  precipitate  was  produced  ;  on  adding  potassa, 
an  orange -brown  precipitate  occurred ;  tannic  acid  yielded  no 
precipitate ;  neither  did  iodine ;  all  the  reactions  proved  the 
presence  of  ammonia  only.  A  portion  of  the  crystalline  mass 
was  now  taken  up  by  dilute  sulphuric  acid,  again  evaporated 
to  near  dryness,  the  residue  almost  neutralized  by  potassa, 
mixed  with  three  times  its  bulk  of  95  per  cent,  alcohol,  and 
the  same  quantity  of  ether,  and,  after  standing  over  night, 
filtered.  The  ethereal  liquid  was  evaporated  spontaneously, 
and  left  a  minute  residue,  which,  on  being  treated  with  potassa 
and  heated,  gave  not  the  slightest  evidence  of  an  alkaline  re- 
action ;  but  phospho-molybdic  acid  appeared  to  create  a  very 
faint  turbidity. 
It  was  possible  now,  that,  by  the  long  maceration  of  the 
leaves  with  sulphuric  acid  and  alcohol,  the  alkaloid  was  de- 
composed. To  ascertain  this,  twelve  ounces  of  fresh  leaves 
were  collected,  infused  in  cold  water,  expressed,  and,  after  a 
second  maceration,  again  expressed.  The  liquid  was  again 
distilled  with  caustic  lime,  and  the  distillate  collected  in  dilute 
sulphuric  acid.  After  spontaneous  evaporation  in  a  current  of 
warm  air,  as  before,  the  residue  was  carefully  neutralized  with 
