o?tob?r"'^iSo™  }    Samples  of  ''Grey''  Cinchona  Bark.  737 
C.  Micraniha.  C.  Nitida.  C.  Peruviana. 
Per  Cent.              Per  Cent.  Per  Cent. 
Quinine  Alkaloid  'I                            o .  08  ....      o .  05  ....  o .  1 1 
Cinchonidine  "  /  
Cinchonine      "                                 4  -49  •  •  •  •      5  64  ....  512 
Quinidine       "                                trace  ....      trace  ....  trace 
Amorphous     ^'                                0.33  ....      0.30  ....  050 
Total  Alkaloid   4  90      ....      5-99      ....  5-73 
The  amount  of  the  obscure  variety  resembling  Pitayensis  was  not 
sufficiently  large  to  warrant  a  separate  analysis,  and  it  was  consid- 
ered important  to  preserve  it  intact  as  a  specimen  for  future  refer- 
ence. 
Mr.  Holmes  has  expressed  the  opinion  with  regard  to  this  ex- 
ceptional parcel  of  grey  bark  that  the  abnormally  high  proportion 
of  cinchonine  indicates  growth  at  a  low  elevation  and  a  hot,  moist 
atmosphere,  basing  his  assumption  on  a  statement  by  J.  E.  Howard 
{Pharm.  Journal,  1883,  XIII,  p.  1013),  that  under  these  circumstances 
cinchonine  is  increased  and  quinine  decreased. 
Mr.  Holmes  also  compares  the  contents  of  this  sample  with 
the  well-known  Ledgeriana  variety  of  Cinchona  Calisaya,  in  which 
quinine  alone  is  present  up  to  a  high  percentage  (the  present  authors 
have  analyzed  samples  of  this  bark  containing  up  to  12  per  cent,  of 
quinine,  expressed  as  sulphate)  and  the  other  alkaloids  only  in  very 
small  proportions.  He  also  puts  forward  the  extremely  interesting 
supposition  that  if,  under  peculiar  circumstances  of  cultivation,  a 
variety  of  Calisaya  bark -can  be  produced  with  such  a  large  propor- 
tion of  quinine,  so  in  the  case  of  Cinchona  Peruviana  or  C.  nitida 
it  is  equally  possible  that  under  favorable  conditions  a  variety 
should  be  found  in  which  the  high  cinchonine  value  peculiar  to  this 
species  is  exaggerated  almost  to  the  point  of  extinction  of  the  other 
alkaloids. 
If  this  interesting  supposition  is  accepted  it  goes  far  to  account 
for  the  peculiar  contents  of  the  samples  under  discussion  which  at 
first  sight  seems  almost  inexplicable. 
For  many  years  past  the  commercial  value  of  bark  for  manu- 
facturing purposes  (as  distinct  from  druggists'  bark)  has  been 
based  almost  entirely  on  the  percentage  of  quinine  present,  but 
quite  recently  the  great  stimulation  of  interest  in  the  hydrogenated 
derivatives  of  the  various  natural  alkaloids  has  caused  the  distri- 
bution of  the  other  principal  bases,  such  as  cinchonidine,  cinchonine, 
