ON  THE  CINCHONAS  OF  COMMERCE. 
51 
lure  ;  very  clear  transverse  fracture,  externally  very  resinous,  with 
short  fibres  internally. 
These  barks  are  produced,  as  we  have  before  observed,  by  the 
branches  of  the  tree  whose  trunk  gives  the  flat,  bark.  Less  alka- 
loid  is  procured  from  them  than  from  the  former,  and,  in  accordance 
with  the  size  of  the  bark,  the  produce  varies  from  15  to  20  grammes 
of  sulphate  of  quinine,  and  from  8  to  10  grammes  of  sulphate  of 
cinchonine  per  kilogramme. 
Cinchona  Carabaya. — This  bark  comes  from  the  province  of 
Carabaya,  by  Arequipa,  to  the  ports  of  Islay,  and  sometimes  of 
Arica  ;  the  thickness  is  from  2  to  3  millimetres  in  the  bulk  of  the 
serons,  which  are,  the  same  as  the  above,  of  the  weight  of  72  to 
75  kilogrammes. 
The  internal  surface  is  of  a  very  even  texture,  but  very  brown, 
and  often  contorted  by  desiccation.  The  external  surface,  instead 
of  longitudinal  ridges,  is  covered  with  small,  almost  black  points, 
which  are  formed  by  the  adherence  of  the  epidermis,  and  sometimes 
in  slanting  ridges.  The  transverse  fracture  is  clear,  fibrous  within, 
with  a  resinous  layer  outside.  It  sometimes  comes  in  very  small 
pieces,  producing  scarcely  12  grammes  of  sulphate  of  quinine  ;  but 
when  the  thickness  we  have  mentioned  is  taken  as  the  average, 
15  to  18  grammes  of  sulphate  of  quinine,  and  4  to  5  grammes  of 
sulphate  of  cinchonine  may  be  obtained. 
Columbian  Cinchonas. — The  cinchona  pitaya,  which  M.  0.  Henri 
has  proved  to  be  so  rich  in  febrifuge  alkaloids,  has  more  especially 
retained  the  name  of  Columbian  cinchona. 
What  is  to  be  understood  by  Columbian  cinchonas  1  It  is  evi- 
dent that  so  general  a  term  can  have  no  precise  meaning.  Car- 
thagena  is  a  port  of  New  Granada  ;  all  the  cinchonas  which  bear 
the  name  of  Carthagena  cinchonas,  are,  therefore,  Columbian  cin- 
chonas, for  New  Granada  is  a  portion  of  Columbia.  All  the  cin- 
chonas which  Mutis  has  discovered  in  New  Granada  are  likewise 
Columbian  cinchonas. 
Cinchonas  known  in  Commerce  as  Carthagena  cinchonas. — 
There  are  several  species  found  in  the  forests  of  New  Granada, 
and  sent  to  Europe  from  the  ports  of  Carthagena,  Saint  Martha, 
and  Maracaybo,  in  serons  of  from  50  to  55  kilogrammes. 
We  owe  the  discovery  of  all  these  cinchonas  to  Senor  Mutis,  a 
Spanish  medical  man. 
