PHARMACY  OF  THE  CINCHONAS. 
399 
or  sixty  assays,  and  yet  it  is  hoped  that  all  the  most  useful  results 
and  deductions  may  be  presented  by  a  few  examples  in  a  small 
space. 
The  Cinchona  adopted  for  the  experiments  was  the  Red  variety, 
because  this  involves  the  greatest  difficulties  in  management,  and 
any  formula  based  upon  it  would  be  more  easily  applicable  to 
the  other  varieties.  A  well-known  lot  of  Red  Cinchona,  in 
the  condition  of  a  very  fine  commercial  powder,  was  taken, 
and  its  proportion  of  impure  alkaloids  was  reconfirmed  by 
the  critical  application  of  Winckler's  full  process  of  assay, 
and  also  by  the  modification  of  his  process  above  given  with 
the  apparatus,  materials  and  other  adjustments,  which  were 
prepared  in  quantity  to  be  used  throughout  the  course  of  research. 
The  proportion  of  impure  alkaloids  was  determined  to  be  34 
grains  to  the  1000  grains  of  the  powder,  or  3-4  per  cent.,  and 
it  was  thus  proved  to  be  a  high  grade  of  Cinchonn,  and  well 
adapted  to  yield  safe  typical  results  for  use  as  a  model.  It  was 
of  a  rich  full  red  color,  compact  and  dense  in  structure  before 
powdering,  was  very  dry,  and  yielded  a  very  fine,  light,  bulky, 
mobile  powder,  of  a  thoroughly  uniform  character  and  quality. 
The  percolations  were  made  without  excessive  care,  or  more 
skill  than  would  be  ordinarily  applied  to  the  process,  but  the 
separation  of  the  different  measures  of  the  different  parts  of  the 
percolate  as  it  came  through  were  made  with  care  and  accuracy 
by  means  of  standard  measuring  flasks  marked  in  the  neck,  and 
by  the  use  of  graduated  pipettes.*  Parallel  experiments  were 
always  carried  along  together,  and  when  unexplained  variations 
occurred,  the  experiments  were  repeated  for  confirmation,  so  that 
neither  care  nor  ordinary  judgment  were  wanting  to  secure  accu- 
racy in  the  results. 
*  It  may  be  usefully  remembered  that  about  29*52  cubic  centimeters  is 
a  fluidounce,  and  that  in  practice  this  becomes  pretty  accurately  30  c.  c. 
Thus,  a  graduated  French  pipette  of  say  50  c.  c.  capacity  becomes  a  most 
useful  instrument  in  the  management  of  our  fluidounce  measure.  Recently 
some  of  the  importers  of  French  and  German  graduated  pipettes  have 
imported  some  of  just  30  c.  c.  capacity,  and  divided  into  0*2  c.  c,  which 
are  still  more  convenient.  By  means  of  these  the  common  "graduate 
measures"  can  be  easily  tested  in  all  their  sub-divisions. 
