AFebr°uYrVP?8a9r7m'}  North  American  Conifer  ce.  93 
pear  to  have  been  published  anything  concerning  its  composition. 
It  is  evident  that  it  contains  resin,  volatile  oil  and  tannin,  and  a 
closer  examination  will  show  the  presence  of  a  considerable  amount 
of  red  coloring,  as  has  already  been  shown  in  the  description  of 
microscopical  structure. 
The  following  results  were  obtained  by  us  on  a  sample  of  bark 
collected  in  June,  1896,  in  eastern  Tennessee.  The  sample  was 
taken  from  the  trunk  of  a  large  tree,  near  the  ground,  and  repre- 
sents an  average  sample  of  the  hemlock  bark  used  in  that  district 
by  tanners.  The  whole  bark  was  taken;  that  is,  it  had  not  been 
"  rossed."  After  having  been  finely  powdered,  50  grammes  were 
submitted  successively  to  the  following  solvents,  moisture  and  ash 
being  added  in  the  proportions  they  were  found  to  exist  in  the  air- 
dry  drug : 
Per  Cent. 
Petroleum  ether  dissolved   070 
Kther 
Absolute  alcohol 
Water 
Alkaline"  water 
Acid 
Boiling  " 
  3*50 
  1574 
 •   392 
  7"5i 
  .  o'8i 
  i'47 
Ash.  in  air-dry  bark   1-42 
Moisture  in  air-dry  bark   673 
Residue  and  undetermined   58*20 
ioo'oo 
The  petroleum  ether  extract  consisted  of  0-036  per  cent,  volatile 
oil,  0-564  per  cent,  of  fat  melting  at  500,  and  o  10  per  cent,  of  wax 
melting  at  65  °. 
The  ethereal  extract  consisted  chiefly  of  resin  and  red  coloring 
matter,  with  a  small  amount  of  tannin. 
The  alcohol  extract  contained  7-90  per  cent,  of  resin  and  decom- 
posed tannin,  known  as  hemlock  red,  the  balance  being  pure  tannin, 
soluble  in  water. 
The  water  extract  contained  neither  mucilage,  sugar  nor  tannin, 
and  only  a  small  amount  of  coloring  matter ;  its  composition  was  not 
further  studied. 
The  alkali  extract  contained  2-29  per  cent,  of  albuminoids,  and  the 
hot  water  extract  consisted  almost  entirely  of  starch. 
The  ash  was  found  to  be  composed  of  magnesium  in  greatest 
abundance,  aluminum,  calcium,  manganese,  potassium  and  traces  of 
phosphoric,  hydrochloric  and  sulphuric  acids. 
