1 4.49 4.23 4.70 3.93 4.48 4.20 4.43
Oil 12.96 13.76 12.28 13.33 12.42 13.07 14.04 14.18
Caffein 1.87 1.81 1.56 1.47 1.26 1.22 1.31 1.28
Caffein,
dry basis 2.03 .... 1.69 .... 1.39 .... 1.44 ....
Crude fiber 20.70 14.75 21.92 14.95 22.23 15.23 22.46 15.41
Protein 9.50 12.93 12.62 14.75 10.43 11.69 8.56 9.57
Protein,
dry basis 10.41 .... 13.68 .... 11.53 .... 9.41 ....
Water extract 31.11 30.30 30.83 30.21 31.04 30.47 31.27 30.44
Specific
gravity,
10 percent
extract 1.0109 1.0101 1.0107 1.0104 1.0105 1.0104 1.0108 1.0108
Bushelweight 47.0 28.2 45.2 27.8 52.2 27.2 48.8 30.2
1,000 kernel
weight 130.60 120.20 167.30 151.35 189.20 165.80 119.52 100.00
1,000 kernel
weight,
dry basis 119.1 115.7 154.1 147.2 171.0 160.1 108.6 96.6
Dextrose .... 0.72 .... 0.81 .... 0.54 .... 0.46
Caffetannic
acid 15.58 17.44 15.37 16.93 16.27 17.13 15.61 16.89
Acidity by
titration
apparent 1.50 2.08 1.47 2.00 1.39 2.13 1.11 1.87

As may be seen in Table II,[138] the caffein content of coffee varies
with the different kinds, a fair average of the caffein content being
about 1.5 percent for _C. arabica_, to which class most of our coffees
belong. However, aside from these may be mentioned _C. canephora_, which
yields 1.97 percent caffein; _C. mauritiana_, which contains 0.07
percent of the alkaloid (less than the average "caffein-free coffee");
and _C. humboltiana_, which contains no caffein, but a bitter principle,
cafemarin. Neither do the berries of _C. Gallienii_, _C. Bonnieri_, or
_C. Mogeneti_ contain any caffein; and there has also been reported[139]
a "Congo coffee" which contained no crystallizable alkaloid whatever.

Apparently the variation in caffein content is largely due to the genus
of the tree from which the berry comes, but it is also quite probable
that the nature of the soil and climatic conditions play an important
part. In the light of what has been accomplished in the field of
agricultural research, it does not seem improbable that a man of
Burbank's ability and foresight could successfully develop a series of
coffees possessed of all the cup qualities inherent in those now used,
but totally devoid of caffein. Whether this is desirable or not is a
question to be considere