204        CAULOPHYLLUM  THALICTROIDES,  (BLUE  COHOSH.) 
by  the  addition  of  strong  alcohol.  The  precipitate  obtained  was 
dissolved  in  water,  and  tested  with  a  solution  of  subacetate  of 
lead,  which  caused  a  white  gelatinous  deposite ;  another  portion 
of  this  watery  solution  gave,  on  the  addition  of  alcohol,  a  white 
precipitate,  these  tests  indicating  the  presence  of  Gum.  A 
portion  of  this  watery  decoction,  when  tested  with  an  aqueous 
solution  of  iodine,  produced  the  characteristic  blue  color,  thus 
proving  the  presence  of  Starch.  No  tannic  or  gallic  acid  was 
detected  on  carefully  adding  the  solution  of  gelatin  and  a  per- 
salt  of  iron.  The  liquid  from  which  the  gum  was  separated  by 
the  addition  of  alcohol,  was  now  freed  from  the  latter  by  evapo- 
rating. I  now  added  to  the  liquid  a  solution  of  the  neutral  ace- 
tate of  lead.  The  precipitate  thus  produced  was  collected  and 
suspended  in  sufficient  water,  and  hydro-sulphuric  acid  in  excess 
was  passed  through  it.  The  precipitate  thus  thrown  down  was 
collected  on  a  filter,  and,  after  heating  the  filtrate  to  drive  off 
the  hydro-sulphuric  acid,  it  was  tested  as  follows :  Chloride  of 
barium  produced  a  cloudiness,  seeming  to  indicate  sulphur  ic'acid, 
which  may  have  been  an  accidental  product  of  the  foregoing  ex- 
periment. Phosphoric  acid  was  shown  by  a  dilute  solution  of 
nitrate  of  silver,  producing  a  yellow  precipitate,  being  again  so- 
luble in  an  excess  of  ammonia.  The  sulphuret  of  lead  obtained 
by  decomposing  the  just  mentioned  lead  precipitate  by  hydro- 
sulphuric  acid,  was  boiled  with  water  and  filtered,  yielding  a  lit- 
tle colored  extractive  matter. 
Alcohol,  sp.  gr.  -835,  was  now  added  to  the  sulphuret  of  lead 
and  raised  to  boiling  point,  and  filtered  while  hot ;  when  shortly, 
on  cooling,  it  deposited  crystals  of  yellowish  tint.  This  crystal- 
line body  was  not  soluble  in  cold  water,  or  in  water  acidulated 
by  sulphuric  acid,  neither  in  a  solution  of  caustic  potassa  or  soda, 
but  was  slightly  soluble  in  cold  and  very  soluble  in  boiling  alco- 
hol, also  soluble  in  ether  and  chloroform.  The  reaction  with  red- 
dened litmus  paper  was  slightly  alkaline.  On  heating  the  crys- 
tals on  platina  foil,  they  first  fused,  giving  off  vapors  of  water 
and  puffed  up  in  a  spongy  coal,  combustion  being  effected  with- 
out residue.  The  crystals  when  placed  under  the  microscope, 
presented  the  prismatic  crystalline  form  with  oblique  termina- 
