AmAJurx8P77arm'}       Analysis  of  Cotton  Root  Bark.  387 
solution  of  acetate  of  lead  (nearly  gviii,  dissolved  in  about  Oiiiss  alco- 
hol, were  required  for  this  purpose),  leaving  a  light  straw-colored  fil- 
trate B. 
The  precipitate  was  diffused  in  about  8  pints  of  alcohol,  and  sul- 
phuretted hydrogen  passed  through  it  until  completely  decomposed. 
The  filtrate  from  the  lead  sulphide  and  washings  were  of  a  very  dark 
red  color  ;  distilled  to  recover  the  alcohol,  and  evaporated,  a  resinous 
coloring  principle  was  left,  which  yielded  a  dark  brown-red  powder, 
resembling  powdered  cochineal,  wholly  soluble  in  alcohol,  ether  and 
aqueous  solutions  of  ammonia,  soda  and  potassa,  and  precipitated  from 
the  three  latter  by  an  acid.  With  potassium  hydrate  it  strikes  a  green 
colpr  ;  petroleum  benzin  seemed  to  dissolve  only  a  portion  of  it.  The 
resin  was  therefore  treated  with  hot  benzin;  about  12  pints  of  a  light 
yellow-colored  solution  was  obtained  which,  on  cooling,  deposited  a 
small  quantity  of  a  peculiar  yellow  substance,  giving  the  same  chemical 
reactions  as  the  resin.  I  was  unable,  however,  to  obtain  a  sufficiently 
large  quantity  of  it  to  thoroughly  investigate  it  ;  the  benzin  solution, 
on  being  evaporated  to  one-half  its  bulk,  did  not  deposit  on  cooling,  as 
was  expected,  but  remained  clear.  The  evaporation  was  then  contin- 
ued until  all  the  benzin  was  driven  off ;  the  result  was  about  one  ounce 
of  a  blackish,  greasy,  semi-fluid  substance,  which  proved  to  be  fat, 
mixed  with  coloring  matter,  and  on  being  boiled  with  caustic  potassa 
formed  soap. 
The  filtrate  and  washings  B  were  reduced  by  distillation  to  about 
10  pints,  and  freed  from  excess  of  lead  by  sulphuretted  hydrogen  and 
filtration.    The  sulphide  of  lead  obtained  was  dried  and  marked  C. 
The  filtrate  was  distilled  to  recover  the  alcohol,  and  evaporated  to 
drive  off  as  much  as  possible  of  the  acetic  acid,  until  about  three  or 
four  ounces  remained.  This  was  mixed  with  six  ounces  of  water, 
thrown  on  a  moist  filter,  and  the  precipitate  washed.  The  filtrate  and 
washings  D  were  of  a  brownish  red  color,  and  a  sweetish  bitter  taste  ; 
the  precipitate  E  was  dark  greenish,  semi-fluid  and  greasy. 
D  was  precipitated  with  subacetate  of  lead,  and  the  precipitate  F 
washed  with  water.  The  filtrate  was  marked  G.  F  was  diffused  in 
water,  decomposed  with  sulphuretted  hydrogen,  and  the  filtrate  evapor- 
ated ;  a  dark  mass  was  left,  having  a  peculiar  somewhat  bitter  and 
astringent  taste.    It  was  tested  for  tannin,  and  found  to  give  a  green 
