562 
Caffeine  in  Tea  and  Coffee. 
5  Am.  Jour.  Pharm. 
I     August,  1921. 
TABLE  XIII.  CAFFEINE  IN  TEA. 
Stahlschmidt      Power  and  Chestnut  Proposed 
Method  Method  Method 
By  Weight.  From  N.  By  Weight  From  N^By  Weight.  From  N. 
% 
c/o 
% 
% 
% 
Black  tea, 
4  • 
  2.83 
2.8l 
3,06 
2.99 
2.98 
2.86 
2.89 
2.87 
3-05 
3.03 
2.94 
2.87 
2.86 
2.84 
3-05 
2.95 
2.92 
2.801 
2.841 
2.82 
2.801 
2.801 
Green  tea, 
5  • 
  1 .04 
I.63 
1. 61 
i-55 
1.70 
1.61 
1.65 
I-S9 
1.69 
1.60 
1.66 
1.77 
I.571 
1.621 
1.58 
1.66 
1.521 
L571 
Green  tea, 
9  • 
  2.092 
1.94 
2.12 
2.01 
2.14 
2.08 
Black  tea, 
10  . 
  2.7I2 
2.63 
2.69 
2.67 
2.62 
2.62 
Black  tea, 
12 
  3-I02 
2.96 
3-20 
3.12 
3-00 
3.15 
3.12 
2.93 
3.03 
2.99 
Satisfactory  methods3  have  beeri  worked  out  for  caffeine  in 
coffee  but  we  have  been  interested  to  try  the  proposed  method  on  that 
substance.  In  two  samples  tried  we  have  obtained  the  following 
results : 
Sample  No. 
Power  and  Chestnut 
Method. 
By  Weight.     From  N. 
Proposed 
Method. 
By  Weight.    From  N. 
% 
% 
% 
% 
15409  ... 
  i-5i 
1-47 
r.49 
1.45 
1.61 
1.49 
15410   
  0.21 
0.17 
0.21 
0.18 
0.28 
0.24 
Sample  15410  was  a  decaffeinated  product.  The  results  suggest 
that  the  method  is  probably  applicable  also  to  coffee. 
1  Results  by  H.  A.  Lepper. 
2  Not  punned  by  treatment  with  potassium  hydroxide. 
3  H.  A.  Lepper,  A.  O.  A.  C-.  Referee  on  Coffee,  Report  of  1920. 
