344  On  the  Detection  of  Exhausted  Ginger.  {Am-juiy;mlrm' 
In  the  hope  of  finding  a  solvent  which  would  dissolve  the  valuable 
portion  of  the  ginger  without  affecting  the  objectionable  resinous 
matters,  we  have  examined  the  action  of  cold  water,  proof-spirit, 
and  rectified  spirit  on  a  number  of  samples  of  ground  ginger  of 
commerce.  The  following  results  were  obtained  by  Mr.  Haywood 
Court.  Sample  A  was  known  to  be  genuine,  but  most  of  the  others 
were  purchased  under  the  Sale  of  Food  and  Drugs  Act,  and  some 
of  them  were  ultimately  admitted  to  contain  an  admixture  of 
exhausted  ginger. 
A. 
B. 
c. 
D. 
E. 
F. 
G. 
H. 
/. 
y. 
K. 
L. 
M. 
Total  ash    
3"54 
5'23 
4-41 
,-«, 
5'53 
7-69 
5'39 
3-6i 
3-19 
2-72 
3-52 
3-29 
— 
4*50 
Ash  soluble  in  hot  water,  .  .  . 
2  36 
2-59 
2*22 
257 
2-87 
2-36 
1-24 
i'45 
0-69 
I'll 
0-97 
i-37 
Alkalinity  of  soluble  ash  as 
K,0,  
096 
o'q6 
0-29 
0-13 
015 
0'20 
027 
0-20 
0-23 
0-23 
Extracted  by  rectified  spirit,  . 
7'33 
770 
737 
622 
8-45 
4^5 
7-09 
6  83 
7-86 
Extracted  by  proof  spirit,  .  j 
21  64 
20-25 
20-80 
18-58 
1070 
10-45 
7-55 
21 '6o 
5-85 
13-00 
16-08 
1 1 78 
12-38 
Containing  ash,   
2'73 
2-30 
2-47 
1 -91 
2-24 
Extracted  by  cold  water,    .  .  . 
H'57 
13-16 
H'95 
H'55 
i4'50 
14  60 
8-14 
8-33 
9-78 
8-51 
7-18 
8-08 
7"39 
Extracted  by  subsequent  treat- 
ment with  proof  spirit,  .  .  . 
977 
9'59 
749 
8-35 
8-51 
7-76 
842 
Extracted  by  subsequent  treat- 
ment with  rectified  spirit, 
I'll 
1-28 
1-31 
1-58 
098 
1-28 
1-71 
Total  extract  by  three  solvents 
used  consecutively  
25-45 
24-03 
23-40 
18-26 
19-27 
I7-55 
17-31 
From  these  results  it  appears  that  the  percentage  of  matter 
extracted  either  by  proof  or  rectified  spirit  affords  very  little  informa- 
tion, the  large  proportion  of  resinous  matters  yielded  both  by 
genuine  and  exhausted  ginger  masking  any  minor  differences.  It  is 
true  that  Dyer  and  Gilbard  consider  that  the  proportion  of  matter 
extracted  by  alcohol  after  complete  removal  of  the  ethereal  extract 
is  a  valuable  item  to  the  analyst ;  but  as  they  found  it  to  range  from 
2-1  to  3  8  per  cent.,  while  in  the  exhausted  samples  it  varied  from 
o-8  to  1 -4  per  cent.,  it  is  evident  that  any  estimate  based  on  this 
datum  must  be  of  a  very  rough  kind. 
On  the  other  hand,  the  proportion  of  extractive  matter  yielded  to 
cold  water  seemed  very  encouraging,  since  the  amounts  dissolved  in 
most  cases  followed  closely  the  proportions  of  soluble  ash.  The 
following  figures  were  obtained  by  Mr.  R.  Waterhouse  by  the 
analysis  of  genuine  ginger  of  known  origin,  supplied  to  us  by  the 
kindness  of  Mr.  W.  Chattaway,  of  Apothecaries'  Hall : 
