556  Coriaria  myrtifolia  as  an  Adulterant.    {A,Ju£St'  fgil™' 
Mediterranean  flora.  Because  of  the  large  content  of  tannin,  it 
has  been  extensively  used  at  times  in  the  dyeing  and  tanning  indus- 
tries. Hence  the  vernacular  names  commonly  applied  to  the  plant, 
"tannin  bush,"  "leather  tree,"  and  "tanner's  shrub." 
Coriaria  myrtifolia  has  been  reported  as  poisonous  to  carnivorous 
animals  and  the  use  of  the  leaves  in  medicine  is  negligible.  It  is 
stated  that  all  parts  of  the  plant  contain  the  colorless,  bitter,  crystal- 
line glucoside  coriamyrtin  which  is  reported  as  having  therapeutic 
properties  resembling  in  this  respect  picrotoxin  and  to  be  of  service 
in  the  treatment  of  blennorrhoea. 
The  Department  of  Agriculture  has  communicated  the  follow- 
ing rough  chemical  test  for  the  detection  of  coriaria  leaves  in  mar- 
joram. "  Place  about  I  Gm.  of  the  sample  in  a  6-inch  porcelain 
dish,  add  200  Cc.  of  water  and  finally  about  5  drops  of  10  per  cent, 
ferric  chloride  solution.  A  light  yellowish  color  of  the  liquid  is 
produced  by  pure  marjoram,  but  when  coriaria  is  present  the  color 
becomes  a  decidedly  dirty  green,  the  intensity  naturally  depending 
upon  the  amount  of  coriaria  present  and  the  time  of  standing.  The 
coloration  is  due  to  the  presence  of  a  large  amount  of  soluble  tannin. 
After  standing  for  a  few  minutes,  the  edges  of  the  particles  of  the 
coriaria  leaves  become  conspicuously  blackened  and  can  be  picked 
out  readily." 
This  proposed  test  is  based  upon  the  well-known  reaction  of 
solutions  of  ferric  salts  with  tannin.  Marjoram  leaves  themselves 
contain  a  tannin  giving  a  greenish-black  reaction  with  ferric  chloride 
and  many  other  leaves,  such,  for  example,  as  those  of  oak  and  chest- 
nut, containing  notable  quantities  of  tannin  would  give  this  reaction 
equally  as  well  as  coriaria  leaves,  and  so  this  test  would  have  no 
value  for  the  positive  determination  of  the  presence  of  coriaria 
leaves. 
Recently  a  sample  of  marjoram  alleged  to  be  adulterated  with 
coriaria  was  referred  to  the  writer  for  examination.  From  this 
sample  a  number  of  small  fragments  of  a  foreign  leaf  were  sepa- 
rated. These  were  quite  distinct  from  the  leaves  of  the  marjoram. 
The  fragments  showed  that  the  leaf  was  pale  green  on  both  surfaces, 
without  pubescence,  and  with  peculiar  wrinkled  markings,  the  tex- 
ture was  thick  and  the  fracture  brittle.  These  fragments  were  ex- 
ceedingly small  leaf  portions,  the  larger  of  those  it  was  possible  to 
separate  out  rarely  measuring  more  than  one-eighth  of  an  inch  in 
the  longest  dimension.    So  thoroughly  had  the  leaves  been  broken 
