452 
Spurious  Gums. 
(  Am.  Jour.  Pharm. 
t      Sept.,  1880. 
Composition  of  opaque  bdellium  : 
Soluble  in  alcohol  (by  difference), 
Gum  soluble  in  water, 
Gum  insoluble  in  water, 
Moisture, 
47-42 
30*01 
ii'oy 
11-50 
lOQ-OO 
2.  African  Bdellium  (Balsamodendron  Africanum)  is  a  gum-resin,  the 
fracture  of  which  is  of  a  dull  slaty  hue,  the  margins  possessing  a 
powdery  resinous  appearance  •,  it  is  hard,  translucent  in  thin  layers,  red 
by  transmitted  light,  has  a  bitter  taste  and  its  slight  aromatic  odor 
recalls  that  of  black  pepper.  Triturated  with  water  it  does  not  form 
an  emulsion,  but  on  standing  gives  a  nearly  bright  mucilage  with  a 
copious  brown  sediment.  The  mucilage  is  very  thick  unless  a  large 
quantity  be  added,  indicating  presence  of  a  considerable  proportion  of 
gum  allied  with  tragacanth. 
The  tincture  of  African  bdellium  is  very  light  yellow  ;  almost  the 
whole  of  the  brown  coloring  matter  is  insoluble  in  alcohol,  chloroform, 
ether  and  turpentine.  Alcohol  extracts  about  15  per  cent.  ;  one-half 
of  the  residue,  including  the  coloring  matter,  is  insoluble  in  water, 
simply  swelling  up  like  tragacanth,  but  dissolves  to  a  brown  solution 
with  a  little  caustic  potash. 
The  tincture  (i  to  6)  gives  no  precipitate  with  bromine,  plumbic 
acetate,  nor  with  ferric  chloride  ;  a  drop  of  liq.  plumbi  subacet.  pro- 
duces a  slight  precipitate,  and  water  renders  it  milky. 
The  mucilage  (made  by  treating  with  water  the  residue  insoluble  in 
alcohol)  is  tasteless,  and  gives  a  slight  precipitate  with  subacetate  but 
none  with  neutral  acetate  of  lead. 
The  estimation  of  moisture  and  ash  gave  13*6  per  cent,  of  the 
former  and  i  16  per  cent,  of  the  latter,  consisting  chiefly  of  calcic 
carbonate. 
Distilled  with  water,  African  bdellium  gave  indication  of  the  presence 
of  a  considerable  quantity  of  volatile  oil  possessing  the  characteristic 
odor  of  the  drug  ;  the  first  portion  which  came  over  was  nearly  color- 
less, the  latter  portion  rather  deep  yellow,  both  lighter  than  water.  The 
small  quantity  operated  on  did  not  admit  of  an  exact  percentage  cal- 
culation. 
Composition  of  African  bdellium  : 
Soluble  in  alcohol  (by  difference),  .  .  ,  15*4 
Gum  soluble  in  water,  ....  33*2 
Gum  insoluble  in  water,  .  .  .  •  37*8 
Moisture,  .  .  .  .  .136' 
loo-o 
