Am*AirSr"  ipSf m'  )      Method  of  Cleaning  Digitalis.  249 
It  will  be  noted  that  the  coarse  lamina  and  petiole  portions,  both 
of  which  were  practically  free  from  adhering  matter,  gave  nearly 
an  identical  amount  of  ash.  This  is  probably  explained  by  the  fact 
that  they  both  consist  primarily  of  parenchyma  tissue.  The  finer 
portion  shows  an  increase  in  the  per  cent,  of  ash  as  was  the  case  in 
the  previous  cleaning  process. 
Some  of  the  separated  petiole  fragments  were  tested  for  digi- 
toxin  by  the  method  previously  described.  The  result,  which  is 
recorded  in  Table  III,  it  will  be  noted,  was  not  more  than  a  very 
faint  trace.  In  view  of  the  large  amount  of  mucilaginous  material 
present  in  the  petioles  we  feel  that  this  statement  should  be  con- 
firmed by  physiological  methods. 
The  Chemical  Examination  of  the  Ash. — On  account  of  the 
possible  effect  of  foreign  inorganic  material  in  the  digitalis,  it  is 
highly  important  that  the  chemical  composition  of  the  same  be 
known.  Qualitative  and  quantitative  examinations  were  therefore 
made  of  the  ashes  obtained  by  incinerating  the  portions  separated 
by  the  cleaning  processes. 
Qualitative  determinations  were  made  on  (A)  ash  of  digitalis 
cleaned  by  screening,  (B)  ash  of  digitalis  middlings,  (C)  ash  of 
digitalis  sif tings,  (D)  ash  of  fine  powder  from  digitalis  sif tings. 
Positive  reactions  were  obtained  from  each  of  the  above  samples 
for  iron,  aluminum,  manganese,  calcium,  magnesium,  potassium, 
sodium,  silicon  and  carbonates.  Negative  results  were  obtained  for 
lead,  mercury,  silver,  bismuth,  copper,  cadmium,  arsenic,  strontium, 
tin,  chromium,  cerium,  nickel,  zinc,  cobalt,  barium,  antimony, 
lithium,  chlorides,  sulphates,  nitrates,  phosphates. 
The  presence  or  absence  of  manganese  in  digitalis  has  been  the 
subject  of  a  number  of  investigations.  Our  results  tend  to  indicate 
that  in  Minnesota  digitalis  it  is  present  only  in  small  amounts.  This 
confirms  the  earlier  results  obtained  by  one  of  us  (Newcomb2),  also 
by  Burmann.3  Manganese  was  positively  identified  in  the  ash  of 
the  clean  digitalis  leaves  by  the  following  tests : 
(a)  In  neutral  solution  by  ammonium  sulphide — flesh-colored  pre- 
cipitate of  MnS. 
(b)  Nitric  acid  solution  with  lead  peroxide — violet-colored  solution. 
(c)  Heating  on  platinum  foil  with  KOH  and  potassium  nitrate — 
green  color. 
2  Newcomb,  Amer.  Jour.  Pharm.,  Vol.  84,  pp.  201-214. 
3  Burmann,  Schweiz.  Wochschr.,  1911,  p.  562. 
