Am.  Jour.  Pharm.  ) 
July  1,  1874.  J 
Detection  of  Aloes. 
333 
•001  gram).  Wormwood  is  soluble  in  water,  with  a  brown  color ;  it 
gives  with  mercurous  nitrate  a  dirty-yellow  precipitate,  becoming 
gray  on  boiling ;  with  subacetate  of  lead  a  brown-yellow,  and  with 
acetate  of  barium  a  brown  precipitate;  H2S04  colors  wormwood 
brown,  Froehde's  test  at  first  brown,  becoming  green,  and  finally 
violet.  Gentian  yields  a  yellowish  opalescent  infusion,  producing 
with  mercurous  nitrate,  after  some  time,  a  very  slight  pulverulent 
precipitate ;  with  acetate  of  barium  from  ammoniacal  solution  a  floe- 
culent  precipitate,  which  yields  with  H2S04  and  HN03  a  yellow,  and 
with  potassa  a  handsome  golden-yellow  solution.  The  resinous  por- 
tion of  agaric  is  soluble  in  alcohol  and  partly  in  hot  water,  yielding 
with  the  latter  an  opalescent  liquid ;  also  in  solution  of  soda,  from 
which  it  is  reprecipitated  by  acids.  It  is  insoluble  even  in  warm 
HN03.  Cold  H2S04  dissolves  it,  with  an  orange  color,  becoming 
brown  on  heating  ;  nitric  acid  added  to  this  solution  causes  decolora- 
tion and  separates  colorless  floccules.  Scammony  dissolves  with  diffi- 
culty*  in  ether,  separating  white  flocks  ;  readily  in  alcohol,  with  a 
greenish-yellow  color ;  insoluble  in  solution  of  sodium  carbonate, 
swelling  to  a  yellow  mass  in  nitric  acid,  readily  soluble  in  H2S04y 
being  orange-colored  at  first,  and  becoming  cherry-red  after  some 
time.  Jalap  resin  is  insoluble  in  water  and  ether,  H2S04  gives  a 
brown  solution,  becoming  blood-red  after  awhile  and  emitting  the 
peculiar  odor  of  jalap. 
On  examining  a  medicine  for  any  of  the  above  substances,  it  is,  if 
necessary,  evaporated  to  dryness,  extracted  with  alcohol,  and  again 
evaporated.  The  dry  powdered  residue  is  exhausted  with  cold  water, 
if  necessary,  concentrated  by  evaporation  in  a  water-bath,  cooled^ 
treated  with  mercurous  nitrate  in  excess,  rapidly  filtered  and  washed. 
The  precipitate  is  dissolved  in  warm  diluted  nitric  acid,  when  colo- 
cynth  will  be  indicated  by  the  yellow  color  of  the  liquid  and  some 
insoluble  flocks ;  in  the  presence  of  wormwood  the  flocks  are  scarcely 
recognizable,  and  the  liquid  is  brown.  Excess  of  ammonia  precipi- 
tates the  mercury,  but  dissolves  colocynth  and  wormwood.  The  fil- 
trate is  evaporated  to  dryness  and  treated  with  warm  acetic  acid ; 
wormwood  will  be  dissolved,  and  colocynth  remains  behind,  the  latter 
giving  with  II2S04  and  with  Froehde's  reagent  the  above-mentioned 
color  reactions.  The  acetic  solution,  on  evaporation,  leaves  a  yellow- 
ish-brown residue,  to  be  identified  by  Froehde's  test  as  stated  above. 
*  ?  Editor  Amer.  Journ.  Pharm. 
