278 
Laboratory  Notes. 
Am.  Jour.  Pharra. 
June,  1888. 
ness  by  means  of  a  water  bath.  The  extract  was  deprived  of  oil  by 
petroleum  spirit,  and  of  theobromine  by  ether,  leaving  sugar  behind. 
The  exhausted  chocolate  was  now  treated  with  100  cc.  of  water  at  15° 
C,  the  filtrate  evaporated,  the  extract  redissolved  in  10  cc.  of  water, 
the  gum  precipitated  by  the  addition  of  alcohol,  and  an  additional 
quantity  of  sugar  was  obtained  by  evaporating  the  filtrate.  The  fol- 
lowing table  gives  the  percentage  of  the  ingredients  : 
Undissolved 
Oil. 
Theobromine. 
Gum. 
Sugar. 
residue. 
I. 
23-52 
1-3 
1-64 
40-74 
32-8 
II. 
22-26 
•92 
1-50 
28-06 
47-26 
III. 
42-4 
1-74 
•34 
2-36 
5316 
IV. 
28-48 
1-52 
-78 
3-86 
65-36 
V. 
31-84 
1-26 
•66 
5-02 
61-22 
Nos.  lY.  and  V.  were  readily  suspended  on  being  stirred  in  hot 
water  or  milk ;  and  all  the  samples  were  easily  diifused  in  these  liq- 
uids by  boiling  for  five  minutes. 
Comparative  value  of  commercial  gingers. — Several  commercial 
varieties  of  ginger  were  procured  by  Frank  M.  Siggins,  Ph.G.,  and 
assayed  for  the  amount  of  resinous  extract ;  8  ounces  of  each  sample 
in  No.  60  powder,  were  exhausted  by  percolation  with  alcohol  of  '820 
spec,  grav.,  the  percolate  was  distilled  until  about  one  fluidounce  re- 
mained, which  was  evaporated  in  a  tared  capsule  by  means  of  a  water 
bath,  until  it  ceased  to  lose  weight ;  the  results  were  as  follows : 
I.  Jamaica,  unbleached 
II.  Jamaica,  bleached.... 
III.  East  India  
IV.  East  India  
V.  African  
VI.  African  
These  results  agree  with  those  of  former  investigators,  showing  that 
African  and  India  gingers  yield  more  resin  than  does  Jamaica  ginger, 
and  would  seem  to  be  preferable  to  the  latter  for  medicinal  use.  The 
unbleached  Jamaica  ginger  was  also  treated  with  petroleum  benzin, 
but  this  menstruum  yielded  only  2*62  per  cent,  of  resinous  extract. 
Sodium  and  ammonium  hydrates  were  tried  to  ascertain  whether 
they  could  be  used  to  form  a  good  extract  soluble  in  water;  but  the 
results  were  not  satisfactory.  By  percolating  the  tincture  of  the  drug 
through  animal  charcoal  it  may  be  made  nearly  colorless,  and  still  re- 
tains the  sharp,  pungent  and  characteristic  taste. 
5"0  per  cent.  resm. 
4-8    "  " 
Cl 
6  65  "  " 
6-57  "  " 
C( 
6-17  "  " 
« 
7-0   "  " 
<< 
