98 
EXTRACTUM  COLOCYNTHIDIS  COMPOSITUM. 
because  so  many  of  the  apples  are  immature  or  blighted  that  the 
seed  in  drying  shrivel  up  to  mere  scales,  and  become  impacted 
in  the  pulp,  or  broken  up  with  it  so  as  to  escape  ordinary  pre- 
caution in  the  separation.  The  proportion  of  perfectly  matured 
apples,  with  clean,  deep  olive  grey  heavy  seed,  does  not  amount 
to  more  than  one-half,  whilst  those  apples  in  which  a  portion  of 
the  seed  is  not  easily  separable,  amount  to  about  5  to  8  per  cent, 
in  the  best  specimens  of  the  commercial  drug. 
The  best  way  to  overcome  these  practical  difficulties  is,  to  es- 
tablish experimentally  a  ratio  for  the  pulp  and  seed  by  the 
amount  of  dry  extract  yielded,  and  the  amount  required  by  the 
formula,  and  then  operate  with  seed  and  pulp  together.  This 
ratio  needs  to  be  corrected  or  newly  obtained  each  time  of 
making  the  extract,  because  in  keeping,  the  seeds  continue  to 
lose  weight  long  after  the  pulp  becomes  dry.  Thus,  entire 
apples,  of  the  various  sizes,  selected  with  care,  after  having  been 
kept  three  years  in  a  dry  store-room,  yield  34  per  cent,  of  pulp. 
Whilst  a  similar  assortment  of  entire  apples  from  the  various  parts 
of  a  recently  purchased  case  yield  25-8  per  cent  of  pulp.  The 
pulp  from  such  perfect  apples,  well  exhausted,  yield  60-7  to  60*8 
per  cent,  of  dry  extract ;  whilst  of  the  same  selections,  taken 
pulp  and  seed  together,  and  treated  in  the  same  manner,  the 
yield  will  vary  widely  according  to  the  state  of  dryness,  from 
15*69  per  cent,  in  the  recent  purchase,  to  20-6  per  cent,  in  that 
long  kept. 
The  yield  of  extract  from  a  careful  average  of  the  above 
mentioned  newly  purchased  case,  taken  seed  and  pulp  together,  on 
the  large  scale,  is  only  14.112  per  cent.,  whilst  that  from  whole 
apples,  seed  and  pulp  together,  is  15*69  per  cent.,  showing  that  the 
average  yield  of  pulp  in  a  case  is  not  that  of  the  entire  apples, 
but  below  it ;  that  is  to  say,  not  25-8  per  cent,  but  23-227  per 
cent,  of  the  whole  weight.  Hence  the  mercantile  assertion  that 
broken  colocynth  is  better  than  whole,  because  the  seed  being 
heavier  and  more  mobile  shake  out  and  are  lost  in  larger  propor- 
tion, is  not  supported  by  fact,  since  whole  apples  yield  nearly 
1-6  per  cent,  more  of  extract  than  broken  and  whole  together. 
The  writer  has  not  been  able  to  find  a  statement  of  the  proper 
composition  of  this  extract,  and  therefore  has  prepared  the  fol- 
owing,  which  is  strictly  that  of  the  XJ.  S.  P.,  except  that  the 
