516 
Quinine  and  Homoquinine. 
Am.  Jour.  Pharm. 
Oct.,  1884. 
sumed  that  Howard  first  had  his  attention  drawn  to  the  presence  of 
quinine  in  the  bark  in  question  by  my  discovery,  which  Fliickiger  had 
communicated  to  him  privately. 
Far  more  important  than  this  point  is  the  question  whether  the 
alkaloid  of  cuprea  bark  then  spoken  of  as  quinine  was  quinine,  or  only 
an  alkaloid  similar  to  it,  homoquinine.  Notwithstanding  that  at  the 
time  I  found  the  alkaloid  in  question  to  correspond  in  every  respect 
with  quinine  obtained  from  true  cinchona  bark,  I  have  once  more  ex- 
amined the  original  cuprea  bark  in  connection  with  my  experiments 
upon  homoquinine,  the  former  results  being  confirmed  most  completely. 
Subsequently,  also,  it  was  pointed  out  by  me  that  in  cuprea  bark 
quinine  is  not  accompanied  by  cinchonidine,  which  has  equally  been 
since  confirmed  by  D.  Howard  and  others.  On  the  other  hand,  accord- 
ing to  my  observation,  quinine  is  always  present  in  cuprea  bark, 
although  the  quantity  is  sometimes  relatively  very  small. 
The  constant  occurrence  of  quinine  in  cuprea  bark  and  the  per- 
sistent absence  from  it  of  cinchonidine  is  so  far  of  special  interest  that 
it  has  been  assumed  in  several  quarters,  especially  by  J.  E.  Howard,1 
that  the  plants  in  their  development  and  growth  are  capable  of  con- 
verting quinine  and  cinchonidine  into  one  another.  Of  course  in  order 
to  make  this  conversion  perceptible  certain  influences  on  the  develop- 
ment of  the  plants  or  their  cultivation  at  different  altitudes  are  required. 
Nevertheless,  the  assumption  of  such  a  change  as  this  during  the 
development  and  growth  of  the  plant  proves  faulty,  since  if  such  a  con- 
version actually  took  place  under  the  conditions  named,  it  would 
certainly  be  possible  to  discover  a  sample  of  cuprea  bark  in  which  at 
least  traces  of  cinchonidine  would  be  present. 
Although  I  am  in  the  position  to  detect  the  smallest  traces  of  cin- 
chonidine with  quinine,  all  the  experiments  made  in  this  direction  with 
cuprea  bark,  as  well  as  with  quinine  obtained  from  that  bark,  have 
remained  without  success,  a  result  that  justifies  me  in  saying  that  the 
formation  of  the  quinine  within  the  plant  takes  place  quite  independently 
of  the  cinchonidine. 
On  account  of  the  absence  of  cinchonidine  it  is  very  easy  to  prepare 
pure  quinine  sulphate  from  cuprea  bark.  This  has  normally,  whilst 
yet  un effloresced,  the  composition  represented  by  the  formula  (C20  H24 
N202)2,S04H2  +  8  H20,  like  the  similarly  pure  salt  obtainable  from 
1  Pharm.  Journal,  [3],  xiii,  1013  ;  Am.  Jour.  Phar.,  1883,  520. 
