26 
Cinchona  Bark. 
( Am.  Jour.  Pharrru 
I    January,  1902. 
such  tedious  experiments  as  Van  Ketel  offers  us  here.1  We  are  to 
the  contrary,  however,  usually  in  more  favorable  conditions  to 
verify  processes  on  industrial  conditions  than  the  apothecary. 
H.  M.  Gordin  published,  recently,  on  page  224  of  the  Archiv  d, 
Pharmacie,  Band  2  39-3-1 901 ,  also  a  method  of  estimation  of  the  total 
amount  of  alkaloids  in  cinchona  bark,  based  upon  an  exhaustion  of  the 
finely  pulverized  bark  (fineness  not  given)  with  alcohol,  acidulated 
with  HC1,  comparing  this  process  with  the  well-known  Prollius 
method,  see  Lyons'  Manual  "page  1 20,  No.  21 3,  employing  ro  (ten) 
gram  drug  and  titrating;  both  latter  peculiarities  (10  gram  drug 
and  titration)  seeming  objectionable  to  me  (J.  B.  N.)  where  a  rich 
bark  of  an  unknown  percentage  of  quinine,  cinchonine,  cinchonidine 
and  amorphous  alkaloid  is  under  examination.2  The  author  would 
oblige  a  good  many  readers  of  the  Archiv  d.  Pharmacie  if  he 
had  quoted  where  one  could  verify  "  nach  meiner  allgemeine 
Methode."3 
Van  Ketel  criticizes  at  length  the  known  methods  of  determin- 
ing the  amount  of  alkaloids  in  cortex  cinchonse,  of  different  varie- 
ties and  species,  for  which  the  reader  is  referred  to  the  original 
article. 
Improving  upon  all  of  them  he  proceeds  as  follows : 
(1)  4  (four)  gramme  airdry  No.  80  powder  (the  original  quotes, 
of  course,  Dutch  requirements  of  fineness  ;  e.  g.,  B.,  40)  is  triturated 
with  2  (two)  gramme  slacked  lime  to  a  homogeneous  mixture.  To 
this  is  added,  in  small  quantities  at  the  time,  4-5  (four  to  five)  c.c. 
Ammonia  water  of  0  96  S.  G.  and  the  whole  mixture  is  brought 
to  a  moist  but  still  non-adherent  powder. 
(2)  Transfer  this  to  a  flask  of  about  300  (three  hundred)  c.c. 
capacity;  add  150  (one  hundred  and  fifty)  c.c.  ethylic  aether  and 
boil  the  mixture  of  bark,  lime  and  ammonia  during  half  (j4)  an 
hour  on  a  safety  water-bath,  using  hereto  an  upright  bulb  con- 
denser or  a  Soxhlet  cooler.  Shake  from  time  to  time,  if  the  mixture 
is  not  stirred  enough  by  the  boiling  process  itself. 
1  Linde's  "  Ueber  das  Ausziehen  von  drogen  zum  Zwecke  der  Alkaloidbestim- 
mung  "  must  not  be  forgotten. 
2  See  also,  "  Die  Pfianzen-Alkaloide  "  von  J.  W.  Bruhl  Braunschweig:  Vieweg, 
1900,  page  162. 
3 1  have  before  me  samples  of  Cort.  cinchonse  S.  containing  respectively  3*2 
per  cent,  and  1*9  per  cent.  Quinine  S. 
