530  Analysis  of  the  Canada  Thistle.  {^Sli^m^' 
Petroleum  ether  dissolved  fat,  wax,  caoutchouc  and  volatile  oil  to 
the  amount  of  1-73  per  cent. 
Ether  (U.  S.  P.)  extracted  1-05  per  cent,  of  the  weight  of  the 
powder.  Water  was  added  to  the  extract  and  the  solution  filtered. 
The  filtrate  was  acid  to  litmus  paper.  Potassium  mercuric  iodide 
and  potassium  tri-iodide  solutions  were  separately  added  to  portions 
of  this  filtrate,  but  no  evidence  of  alkaloids  was  shown.  Fehling's 
solution  was  not  reduced  either  before  or  after  boiling  a  portion  of 
the  filtrate  with  acid,  thus  showing  the  absence  of  glucosides  in  this 
extract.  The  acid  substance  will  be  given  further  notice  in  the 
course  of  this  paper. 
Absolute  alcohol  removed  2-31  per  cent,  of  soluble  matter  from 
the  material.  Of  this  amount  1-05  per  cent,  was  resin  and  chloro- 
phyll. The  remainder  was  soluble  in  water.  A  small  amount  of 
glucose  was  indicated  by  Fehling's  solution,  which  was  applied  to  a 
portion  of  this  water  solution.  Potassium  mercuric  iodide  and 
potassium  tri-iodide  solutions  gave  reactions  for  alkaloids  with  sepa- 
rate portions  of  the  water  solution.  The  substance  giving  these 
reactions  was  shaken  out  of  the  water  solution,  after  making  the 
latter  alkaline,  with  ether  and  chloroform.  This  principle  was  also 
further  investigated,  as  will  be  shown  hereafter. 
Distilled  water  dissolved  H'47  per  cent,  of  organic  matter, 
including  4-37  per  cent,  of  mucilage,  2  97  per  cent,  of  dextrin,  and 
a  trace  of  glucose.  Alkaline  water  extracted  3-17  per  cent,  of  pectin 
and  albuminous  matter,  and  other  plant  principles  to  the  total 
amount  of  10-68  per  cent. 
Acidulated  water  removed  7-94  per  cent,  of  organic  solids  from . 
the  residue,  after  the  treatment  with  the  alkaline  water. 
Treatment  with  chlorine  water  revealed  5-08  per  cent,  of  lignin. 
The  residue  from  this  process  contained  39-94  per  cent,  of  cellulose. 
The  material  not  accounted  for  by  the  foregoing  figures  consisted  of 
1-40  per  cent,  loss  during  analysis. 
Experiments  were  made  on  a  larger  quantity  of  material  in-  order 
to  further  investigate  the  acid  and  alkaloidal  substances  indicated 
by  the  proximate  analysis.  To  make  these  experiments,  about  450 
grammes  of  the  ground  plant  were  exhausted  by  percolation  with 
official  alcohol.  Nearly  all  of  the  menstruum  was  recovered  by 
distillation,  and  the  extract  treated  with  about  five  times  its  volume 
of  distilled  water  acidified  with  hydrochloric  acid.    The  mixture 
