Phy  to  chemical  Research.  {Amk£ch  i^hi7rm' 
C11H1203,  might  serve  as  a  starting  point  for  the  synthesis  of 
cotarnine.  As  is  well  known,  the  base  cotarnine,  C12H1504N,  is  an 
oxidation  product  of  the  opium  alkaloid  narcotine,  C22H2307N,  and 
under  the  name  of  "  stypticine "  it  is  used  to  some  extent  medic- 
inally. By  an  extended  series  of  complex  reactions  it  was  indeed 
found  possible  to  pass  from  myristicin  to  cotarnine,  or,  in  other 
words,  from  a  constituent  of  nutmeg  to  a  derivative  of  an  opium 
alkaloid.  Inasmuch  as  cotarnine  may  be  combined  with  meconine, 
C10H10O4,  to  form  narcotine,  and  meconine  has  in  turn  been  synthe- 
sized from  guaiacol,  C6H4<^j^^3,  the  complete  synthesis  of  narco- 
tine has  been  effected. 
It  has  not  been  the  intention  to  devote  the  time  this  evening  ex- 
clusively to  such  vegetable  products  as  are  obtained  from  the  Far 
East,  but  brief  consideration  may  be  given  to  another  Indian  plant, 
on  account  of  both  its  chemical  and  physiological  interest.  The 
plant  in  question  is  known  botanically  as  Gymnema  syhestre  R.  Br., 
which  belongs  to  the  family  of  Asclepiadacece,  and  is  indigenous 
to  Banda  and  the  Deccan  Peninsula.  Although  various  medicinal 
properties  have  been  attributed  to  it  by  the  Hindus,  it  was  brought 
more  prominently  to  notice  some  years  ago  on  account  of  the  ob- 
servation that  the  leaves,  when  chewed,  have  the  property  of  render- 
ing imperceptible  the  sweet  taste  of  sugar  and  other  saccharine  sub- 
stances, and  also,  but  in  a  less  marked  degree,  the  taste  of  many 
bitter  substances.  This  effect  is  due  to  a  substance  which  appears 
to  have  a  selective  action  upon  the  nerve  fibers  or  nerve  endings 
concerned  with  taste,  and  has  been  designated  gymnemic  acid.  The 
most  recent  investigation10  of  this  product  has  shown,  however,  that 
as  originally  prepared  it  was  not  homogeneous,11  and  even  after 
extended  treatment  for  the  purpose  of  purification  it  could  not  be 
obtained  crystalline,  nor  in  a  form  which  would  permit  of  its  more 
definite  characterization. 
Apart  from  the  constituent  of  gymnema  leaves  to  which  the 
peculiar  physiological  property  referred  to  is  due,  they  have  been 
found  to  contain  another  substance  of  chemical  interest,  namely,  a 
lsevorotatory  modification  of  quercitol,  C6H7(OH)5.H20.12  The 
10  Power  and  Tutin,  Pharm.  Journ.,  1904,  73,  pp.  234-239. 
11  Hooper,  Pharm.  Journ.,  1887,  17,  p.  867,  and  Chemical  News,  1889,  59, 
p.  159. 
12  Power  and  Tutin,  Jour.  Chem.  Soc.,  1904,  85,  pp.  624-629. 
