AmMarch,S96arm'}  Aristolochia  Argentina.  141 
— aristin.  Previously,  however,  Pohl  had  investigated  various  spe- 
cies of  Aristolochia,  and  described  a  finely  crystalline  yellow  sub- 
stance under  the  name  of  aristolochine.  But  as  this  substance  is  of 
an  acid  nature,  it  is  thought  better  to  call  it  aristolochic  acid,  so  as 
not  to  confuse  it  with  the  alkaloid. 
Hesse  has  since  continued  his  investigations,  and  thereby  made 
clearer  the  chemistry  of  these  substances. 
Aristolochine. — This  principle  is  obtained  by  treating  the  roots 
with  soda  and  afterward  extracting  with  alcohol.  The  residue  left 
after  distilling  off  the  alcohol  is  treated  with  sodium  carbonate  and 
ether,  and,  on  shaking  the  ethereal  solution  with  dilute  tartaric  acid 
and  decolorizing  with  charcoal,  the  base  is  precipitated  on  the  addi- 
tion of  ammonia  and  separated  with  ether.  It  is  a  colorless,  distinctly 
crystalline  substance.  In  alcoholic  solution  it  turns  litmus  paper 
blue  and  completely  neutralizes  acids,  but  the  salts  are  amorphous. 
Indifferent  Substance. — When  atmospheric  air  containing  ammo- 
nia is  passed  through  an  ether  extract  of  the  crushed  roots,  the 
liquid  deposits  red  crystals.  Afterwards  the  ether  is  shaken  with 
acid,  and,  on  distillation,  a  residue  remains  which  yields  crystals 
of  palmityl  phytostearin,  G42H7402,  melting  at  820  C,  and  a  minute 
quantity  of  aristolin,  C15H2803. 
Aristinic  Acid  (C18H13N07). — The  red  deposit  from  the  ammo- 
niacal  extract  consists  principally  of  the  ammonia  salt  of  this  acid. 
It  forms  greenish-yellow  laminae  and  needles,  melting  at  275 0  C, 
with  decomposition. 
Aristidinic  Acid  (C18H13N07). — This  acid  remains  in  the  acetic  acid 
solution  from  which  aristinic  acid  has  been  separated.  It  is  soluble 
in  ether  and  crystallizes  in  small  needles. 
Avistolic  Acid  (C15H13N07  or  C15HnN07).— On  treating  the  alkaline 
solution  from  which  the  acids  previously  mentioned  have  been  sepa- 
rated with  hydrochloric  acid,  and  afterward  shaking  with  ether,  an 
orange-yellow  crystalline  residue  is  obtained  on  evaporating  the 
solvent.  The  crystals  melt  between  2600  and  2700  C.  This  acid 
dissolves  in  strong  sulphuric  acid  with  dark  green  color,  this  char- 
acter indicating  relation  to  the  other  acids  and  also  to  the  aristolo- 
chine of  Pohl. 
These  substances  probably  exist  in  other  varieties  of  the  genus 
Aristolochia,  but  an  examination  of  the  roots  of  Aristolochia  lonca 
has  yielded  only  negative  results. 
