[Illustration: FORMULA FOR CAFFEIN, SHOWING ITS RELATION TO THE PURIN GROUP] Gorter states that caffein exists in coffee in combination with chlorogenic acid as a potassium chlorogenate, C_32_H_36_O_19, K_2(C_8_H_10_O_2_N_4)_2.2H_2_O, which he isolated in colorless prisms. This compound is water-soluble, but caffein can not be extracted from the crystals with anhydrous solvents. To this behavior can probably be attributed the difficulty experienced in extracting caffein from coffee with dry organic solvents. However, the fact that a small percentage can be extracted from the green bean in this manner indicates that some of the caffein content exists therein in a free state. This acid compound of caffein will be largely decomposed during the process of torrefaction, so that in roasted coffee a larger percentage will be present in the free state. Microscopical examination of the roasted bean lends verisimilitude to this contention. [Illustration: PLANTER'S BUNGALOW WITH COFFEE TREES IN FLOWER, MYSORE] [Illustration: COOLIES BAGGING COFFEE ON THE DRYING GROUNDS] [Illustration: COFFEE SCENES IN BRITISH INDIA] TABLE II--COFFEE ANALYSES Santos Green | Santos Roasted | | Padang Green | | | Padang Roasted | | | | Guatemala Green | | | | | Guatemala Roasted | | | | | | Mocha Green | | | | | | | Mocha | | | | | | | Roasted | | | | | | | | Moisture 8.75 3.75 8.78 2.72 9.59 3.40 9.06 3.36 April 20th Moisture September 20th 8.12 6.45 8.05 6.03 8.68 6.92 8.15 7.10 Ash 4.41 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