502  Notes  on  Cinchona  Bark.  {Am-&%I^im' 
C.  officinalis  from  trees  which  were  coppiced  three  years  ago.    It  gives 
quinia  2*2  per  cent.,  cinchonidia  *2  per  cent.,  quinidia  1*5  per  cent., 
and  cinchonia  3*3  per  cent. 
The  stem  bark  from  this  plantation,  at  the  time  when  the  trees  were 
cut  down, gave  :  quinia  2*6  per  cent.,  cinchonidin  *6  per  cent.,  cinchonin 
i*  per  cent.,  and  but  a  trace  of  quinidin. 
We  find,  therefore,  that  in  this  sample  the  ordinary  tendency  of  root 
bark  to  produce  the  dextrogyrate  alkaloids  is  developed  to  a  most 
unusual  degree,  the  percentage  of  quinidin  is  a  most  extraordinary  one 
for  bark  from  C.  officinalis. 
I  have  also  received  from  Darjeeling  a  very  interesting  sample  of  the 
bark  of  C.  succirubra  accidentally  renewed.  It  is  entirely  the  produce 
of  accidental  injuries  to  the  trees  (not  deep  enough  to  injure  the  cam- 
bium, and  prevent  the  bark  forming  over  the  whole  surface),  no  pro- 
tection whatever  having  been  given  where  the  bark  was  removed. 
The  result  is  as  successful  as  could  have  been  expected  from  renew- 
ing under  the  most  favorable  conditions,  the  contained  alkaloids  being, 
quinia  2*3  per  cent.,  cinchonidia  1*5  per  cent.,  cinchonia  1*2  per 
cent.,  quinidia  *i  per  cent. 
Two  parcels  of  the  stem  bark  sent  over  at  the  same  time  from  this 
plantation  gave,  first,  quinia  *8  per  cent.,  cinchonidia  i'2  per  cent.,, 
cinchonia  1*2  per  cent.,  and  secondly,  quinia  'g  per  cent.,  cinchoni- 
dia i*i  per  cent.,  cinchonia  2'0  per  cent. 
The  improvement  in  value  in  renewed  bark  is,  therefore,  not  owing 
to  the  covering,  but  is  found  equally  in  this  accidentally  renewed  bark, 
and  it  would  seem  that  the  mossing  is  valuable  chiefly  as  enabling  the 
tree  to  produce  the  renewed  bark  with  as  little  injury  to  its  health  as 
possible.  It  will  probably  be  found  that  a  less  perfect  shelter  than  moss 
may  in  some  circumstances  be  sufficient  to  preserve  the  health  of  the 
tree  under  this  process.  , 
It  has  been  proposed  by  M.  Moens  to  shave  off"  the  outer  layers  of 
bark  without  cutting  quite  through  the  bark.  No  doubt  the  cellular 
portion  of  the  bark  is  richer  in  alkaloids  than  the  inner  fibrous  layer 
[vide  "  Quinology  of  the  East  Indian  Plantations,"  by  J.  E.  Howard, 
F.R.S.,  pp.  23,  24  and  38),  although  the  corky  excrescences  thrown 
out  by  the  variety  of  C.  officinalis,  the  "  knotty  bark  of  Jussieu,"  con- 
tain but  little  alkaloid  ("  Pharmaceutical  Journal,"  third  series,  No. 
454,  p.  769  ;  u  Quinology  of  the   East   Indian   Plantations,"  p.  70). 
