'^'"^'Stiyim^™'}    Adulterations  of  Commercial  Pepper. 
483 
(a)  That  pure  pepper  may  contain  from  nine  to  twelve  per  cent,  of 
moisture. 
(6)  That  the  amount  of  ash  in  pure  pepper  ought  not  to  exceed  six 
per  cent. 
(c)  That  pure  pepper  contains  from  five  to  eight  per  cent,  of  piper- 
ine  and  resin,  and  that  less  than  4' 5  per  cent,  is  evidence  of  sophisti- 
cation. 
Authorities  differ  widely  upon  the  relative  amounts  of  the  above 
constituents.    The  extremes  given  are  : 
Piperine  and  resin  5-25  to  8-15  per  cent. 
Moisture  9*22  to  14-36  " 
^sh  4-35  to  8-89 
Niederstadt  says  that  genuine  black  pepper  should  yield  7*6tj  per 
cent,  of  piperine.  This  is  certainly  in  excess  of  the  amount  usually 
obtained,  and  a  sample  not  reaching  this  limit  is  not  necessarily  im- 
pure. Probably  from  4*5  to  5*5  per  cent,  is  nearer  correct.  It 
should  be  remembered  that  the  source  from  whence  the  pepper  was 
originally  obtained,  as  well  as  the  conditions  to  which  it  has  been 
subjected  after  being  taken  from  the  plant,  have  much  to  do  with  the 
results  of  a  chemical  determination  ;  for  pure  peppers  differ  considera- 
bly in  their  important  constituents,  especially  if,  after  curing,  they  have 
been  subjected  to  varying  conditions.  The  appearance  of  the  evaporated 
ethereal  extract  must  be  carefully  noted,  as  it  affords  an  excellent 
clue  to  possible  adulteration.  It  should  be  dry,  somewhat  scaly,  and 
the  resin  should  show  numerous  projecting  crystals  of  piperine.  If  it 
has  a  dark,  oily  appearance  and  is  mostly  amorphous,  adulteration  is 
indicated. 
All  peppers,  whether  pure  or  not,  contain  more  or  less  sand,  and 
the  excess  in  weight  of  ash  in  some  of  the  samples  containing  the  nor- 
mal amount  of  piperine  and  resin  is  attributable  to  sand,  since  in  each 
case  there  was  a  sufficient  amount  of  insoluble  residue  after  treating 
with  hydrochloric  acid  to  account  for  it.  No  determination  of  starch 
was  made,  since  the  ingredients  used  as  adulterants  frequently  con- 
tain more  starch  than  the  pepper  itself ;  hence  such  a  determination 
would  be  of  doubtful  value. 
Physical  Examination. — This  mode  of  examination  is  absolutely 
essential  to  a  thorough  analysis  of  pepper,  since  many  of  the  impuri- 
ties are  much  better  detected  by  it  than  by  chemical  tests.  The  ex- 
aminer must  familiarize  himself  with  the  structure  of  pure  pepper  and 
