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ON  THE  ALKALOIDS  OF   THE  CINCHONAS, 
ON  THE  ALKALOIDS  OF  THE  CINCHONAS. 
By  L.  Pasteur. 
It  is  about  half  a  century  since  cinchonine,  previously  noticed 
by  Dr.  Duncan  of  Edinburgh,  was  first  isolated  by  Gomes,  a  physi- 
cian of  Lisbon.  To  its  presence  he  attributed  the  action  of  the 
cinchona  barks ;  but  he  misunderstood  its  alkaline  nature,  which 
was  not  thoroughly  appreciated  until  about  1820  by  MM.  Pelletier 
and  Caventou;  at  this  period  these  chemists  also  discovered  quinine. 
About  twelve  years  afterwards,  two  other  French  chemists  recog- 
nized a  third  alkaloid,  to  which  they  gave  the  name  of  quinidine, 
in  the  yellow  Jesuit's  bark.  In  the  year  1829,  Sertuerner,  who 
had  already  become  celebrated  by  his  discovery  of  morphine, 
pointed  out  the  existence,  in  the  mother-waters  of  sulphate  of 
quinine,  of  an  uncrystallizable  base,  which  he  called  qiiinoidine, 
and  to  which  he  attributed  wonderful  febrifuge  properties. 
The  general  properties  of  quinine  and  cinchonine  are  pretty  well 
known  ;  but  with  regard  to  quinidine  and  quinoidine,  the  most  con- 
tradictory opinions  prevail.  I  believe  I  have  got  rid  of  all  the 
difficulties.  The  results  of  my  labors  also  exhibit  quite  new 
molecular  relations  between  the  various  alkaloids  of  these  barks. 
The  following  are  the  new  facts  at  which  I  have  arrived. 
1.  Cinchonicine. — When  cinchonine  in  any  saline  combination 
is  exposed  to  the  action  of  heat,  it  is  converted  into  a  new  base 
isomeric  with,  but  quite  distinct  from  cinchonine.  I  call  it  cincho- 
nicine. All  the  salts  of  cinchonine  may  serve  for  the  preparation 
of  cinchonicine  ;  but  in  order  that  the  conversion  may  be  easily 
and  completely  effected,  it  is  necessary  to  place  the  salt  in  certain 
conditions.  In  general,  when  salts  of  cinchonine  are  healed,  they 
fuse  and  become  decomposed  immediately  ;  and  if  the  fusion  of  the 
salt  be  not  effected  by  some  means  at  a  temperature  sufficiently 
distant  from  the  point  of  decomposition,  the  cinchonicine  will  cer- 
tainly be  formed,  but  destroyed  immediately  by  the  further  action 
of  the  heat.  Ordinary  sulphate  of  cinchonine,  for  instance,  when 
heated  directly,  becomes  fused  and  then  immediately  destroyed, 
furnishing  a  fine  red  resinous  matter,  which  is  a  product  of  the 
alteration  of  cinchonicine.  But  if  a  little  water  and  sulphuric 
acid  be  added  to  the  sulphate  before  subjecting  it  to  the  action  of 
heat,  it  remains  fused  even  after  the  expulsion  of  all  the  water  at 
