"The detection of the presence of chicory, caramel, and some sweet roots, as turnips, carrots, and parsnips, is quite easy. If a few grains of the suspected sample are placed on the surface of water in a glass vessel, beaker, or tumbler, each particle of chicory, etc., will become surrounded by a yellow-brown cloud which rapidly diffuses through the water until the whole becomes colored. Pure coffee under the same conditions gives no sensible color until after the lapse of about fifteen minutes. Caramel (burnt sugar) of course colors the water very deeply. Dandelion root gives a deeper color than coffee, but not as deep as chicory. The same is true of bread raspings. Beans and pease give much less color to the water than pure coffee. They can be readily detected by the microscope, as can roasted figs and dates or date-stones." (Mrs. Richards, in "Food Materials and Their Adulterations.") Coffee is said to owe its refreshing properties to (_a_) caffeine, (_b_) a volatile oil developed by heat, not contained in the unroasted bean, and to (_c_) astringent acids. Coffee diminishes the sensation of hunger, exhilarates and refreshes, and decreases the amount of wear and tear of the system. Its composition, according to Payen, is as follows: Cellulose 34.000 Water 12.000 Fatty matter 13.000 Glucose, dextrine, and undetermined vegetable acids 15.500 Legumin, casein, etc. 10.000 Chlorogenate of potash and caffeine 3 to 5.000 Nitrogenized structure 3.000 Caffeine .800 Essential oil .001 Aromatic essence .002 Mineral substances 6.970 It is difficult to determine whether coffee may be classed as a food, but that it has value as an adjunct to true nutrients there can be no doubt. There is a general agreement among physiologists that coffee is invigorating, that it aids digestion both in the sick and the well, that it is capable of allaying or retarding waste and thereby acting indirectly as a food. But the mistake should not be made that coffee will _replace_ food. Coffee may be compared in its effects on the system to beef-tea--it is valuable for its flavors rather than for actual nutritious principles.