Am  Au0gu",i879!rm' }  Chemical  Investigation  of  Mac  alio  Bark.  3  93 
separated  from  the  inner  bark  in  rather  large  pieces,  and  is  sometimes 
perforated  by  insects.  The  liber  has  a  reddish  color,  similar  to  that  of 
-cinchona  and  deeper  upon  the  inner  surface,  which  is  slightly  striate  ; 
it  is  about  two-thirds  of  the  thickness  of  the  bark  and  has  very  tough 
•fibres,  forming  a  compact  tissue. 
The  bark  seems  to  be  easily  separated  from  the  plant,  and  on  drying 
'becomes  somewhat  curved,  and  the  broad  pieces  are  slightly  rolled  upon 
the  inner  surface  from  both  edges.  The  bark  has  a  rather  astringent 
taste,  and  after  masticating  it  for  some  time,  it  imparts  a  reddish  color 
to  the  saliva. 
For  obtaining  the  extract,  500  grams  of  the  coarsely  powdered  bark 
were  boiled  for  two  hours  in  5  liters  of  water,  care  being  taken  to 
replace  the  water  which  evaporated.  When  cold,  the  mass  was 
expressed  and  the  filtered  liquid  evaporated  in  a  water-bath,  yielding 
100  grams  of  a  brown-red  extract,  which  became  darker  on  exposure 
without  showing  other  changes. 
The  powdered  bark  was  displaced  with  ether  containing  one-tenth 
of  water  ;  the  liquid  separated  into  two  layers,  the  upper  one  being 
greenish,  and  consisting  mainly  of  a  solution  of  resin  in  ether.  The 
lower  stratum  was  an  aqueous  solution  of  tannin,  yielding,  on  evapora- 
tion, 2  per  cent,  of  the  weight  of  the  bark.  This  macallo-tannic  or 
yabo-tannic  acid  is  yellow  in  transmitted  and  reddish-yellow  in  reflected 
light,  has  a  very  astringent  taste,  is  easily  soluble  in  water  with  a  deep- 
reddish  color,  has  a  slight  acid  reaction  and  produces,  with  ferric  salts, 
a  greenish-black  precipitate. 
For  obtaining  the  alkaloids  500  grams  of  the  bark  were  macerated  for 
twenty-four  hours  with  water  acidulated  with  hydrochloric  acid,  then 
boiled  for  an  hour,  and  after  cooling,  the  liquid  was  filtered  and  precip- 
itated with  sufficient  milk  of  lime.  The  filtrate  from  the  precipitate 
was  acidulated  with  sulphuric  acid,  freed  from  the  calcium  sulphate  by 
filtration,  and  concentrated,  when  10  grams  of  fine  white  shining  need- 
les were  obtained,  having  an  acid  taste,  being  insoluble  in  alcohol, 
nearly  insoluble  in  water,  and  requiring  150  parts  of  diluted  sulphuric 
acid  for  solution. 
The  mother  liquor,  on  further  evaporation,  acquired  a  blackish  color 
and  yielded  few  impure  crystals.  The  solution  of  the  crystals  yielded, 
with  weak  potassa  solution,  a  gelatinous  whitish  precipitate  which,  after 
drying,  weighed  2  grams,  was  amorphous,  pulveruleat,  tasteless,  insol- 
