MATIAS  BARK. 
217 
Experiment  2nd  To  the  remaining  material  in  the  retort 
was  added  half  a  pint  of  water,  and  strongly  pressed  and  fil- 
tered. This  decoction  had  an  intensely  bitter  taste,  but  was 
almost  deprived  of  the  aromatic  odor  of  the  bark.  To  a  small 
portion  of  the  decoction  was  added  a  few  drops  of  the  muriated 
tincture  of  iron,  which  caused  a  slight  deepening  of  color,  but 
produced  no  precipitate  even  after  twenty-four  hours  standing. 
To  another  portion  of  the  decoction  was  added  a  warm  solution 
of  gelatine,  but  no  change  was  produced.  These  two  experi- 
ments plainly  show  the  absence  of  tannin.  To  another  portion 
of  the  decoction  was  added  a  few  drops  of  strong  solution  of 
acetate  of  lead,  when  a  heavy  precipitate  was  thrown  down,  in- 
dicating the  presence  of  gum.  A  few  drops  of  tincture  of  iodine 
were  dropped  into  about  an  ounce  of  the  decoction,  which  occa- 
sioned a  blackish  blue  color  throughout  the  liquid,  and  dis- 
appeared on  being  heated.  By  this  was  recognized  the  presence 
of  starch. 
Experiment  3d  A  cold  infusion  of  an  ounce  to  a  pint  was 
made  and  filtered ;  to  about  an  ounce  of  this  infusion  was  added 
a  saturated  solution  of  corrosive  sublimate,  causing  a  floculent 
precipitate. 
Several  ounces  of  the  infusion  were  then  boiled  in  a  matrass ; 
this  somewhat  diminished  the  clearness  of  the  infusion,  and  after 
being  set  aside  for  several  hours,  a  slight  precipitate  had  de- 
posited. 
Experiment  4th. — An  alcoholic  tincture  (2  oz.  to  1  pint)  had  a 
deep  red  color  and  an  exceedingly  persistent  bitter  taste.  An 
ounce  of  this  tincture  thrown  upon  some  water,  a  considerable 
amount  of  resinous  matter  deposited,  which  on  being  collected 
and  after  being  kneaded  in  water,  presented  all  the  appearance 
of  resin,  and  which  when  applied  to  the  heat  of  a  lamp,  instantly 
fused  and  ran  down  in  drops,  while  a  portion  took  fire  and 
burned  with  much  smoke. 
Experiment  5th. — Two  ounces  of  the  coarsely  powdered  bark 
were  thoroughly  exhausted  with  alcohol  of  -835,  then  by  evapor- 
ating this  tincture  there  was  produced  195  grains  of  extract,  of 
an  intensely  bitter  and  aromatic  taste.  To  the  powdered  bark, 
after  being  exhausted  with  alcohol,  and  while  it  was  still  in  the 
percolator,  cold  water  was  added  until  it  passed  nearly  colorless  ; 
