'A^Susrtj902fm'}    Coffee:  Its  History  and  Commerce.  371 
In  beans  and  leaves  of  coffee,  y2  percent.;  in  tea,  2  to  4  per  cent.; 
in  yerba  mate,  5  per  cent. ;  in  guarana,  5  per  cent.  According  to 
Payen,  cocoa  contains  2  per  cent,  theobromine.  Reports  of  analyses 
vary  much,  but  there  seems  to  be  no  doubt  that  coffee  contains 
less  of  the  alkaloidal  principle  than  any  of  the  other  beverages. 
The  changes  effected  by  roasting  are  shown  in  the  following 
analyses : 
CHEMICAL  COMPOSITION  OF  COFFEE  (PROF.  HASSAEE). 
Raw.  Roasted. 
Per  Cent.        Per  Cent. 
Caffeine  (theine)   no  ro6 
Fat   11*42  8*30 
Extractives  (caramel,  gum,  tannin)     .......  14*03  26*28 
Gluten   io*68  12*03 
Cane  sugar   8*i8  1*84 
Water   8*26  0-36 
Cellulose,  etc   42*36  44*96 
Ash   3*97  5*17 
100*00  100*00 
AVERAGE  COMPOSITION  OF  ROASTED  COFFEE  (a.  H.  CHURCH). 
In  One  Pound. 
Per  Cent.      Ounces.  Grains. 
Caffeine  (theine)   i'o  o  70 
Pat  or  oil  12*5  2  o 
Tannin   5*0  o  350 
Minor  extractives  14*4  2  133 
Albuminoids  12*5  2  o 
Water    2*0  o  140 
Cellulose  48*0  7  297 
Mineral  matter   4*6  o  322 
ioo*o  1  lb. 
FOOD  ANALYSIS  OF  UNROASTED  COFFEE  ( PAYEN ). 
Per  Cent. 
Flesh-formers  i4'75 
Heat-givers  66*25 
Water  12*00 
Mineral  matter     7*00 
100*00 
VIII.  EFFECTS. 
In  the  United  States  coffee  is  an  extremely  popular  beverage.  It 
is  estimated  that  about  70  per  cent,  of  our  people  are  habitual  coffee 
drinkers.  As  a  rule  we  use  a  decoction  of  only  one-half  the  strength 
of  that  used  in  Brazil,  France,  Turkey  and  some  other  countries. 
