Aside from adulteration by mixing substitutes with ground coffee, and an occasional case of factitious molded berries, the main sophistications of coffee comprise coating and coloring the whole beans. Coloring of green and roasted coffees is practised to conceal damaged and inferior beans. Lead and zinc chromates, Prussian blue, ferric oxid, coal-tar colors, and other substances of a harmful nature, have been employed for this purpose, being made to adhere to the beans with adhesives. As glazes and coatings, a variety of substances have been employed, such as butter, margarin, vegetable oils, paraffin, vaseline, gums, dextrin, gelatin, resins, glue, milk, glycerin, salt, sodium bicarbonate, vinegar, Irish moss, isinglass, albumen, etc. It is usually claimed that coating is applied to retain aroma and to act as a clarifying agent; but the real reasons are usually to increase weight through absorption of water, to render low-grade coffees more attractive, to eliminate by-products, and to assist in advertising. METHODS OF ANALYSIS OF COFFEES[185] (_Official and Tentative_) (Sole responsibility for any errors in compilation or printing of these methods is assumed by the author.) GREEN COFFEE 1. _Macroscopic Examination--Tentative_ A macroscopic examination is usually sufficient to show the presence of excessive amounts of black and blighted coffee beans, coffee hulls, stones, and other foreign matter. These can be separated by hand-picking and determined gravi-metrically. 2. _Coloring Matters--Tentative_ Shake vigorously 100 grams or more of the sample with cold water or 70 percent alcohol by volume. Strain through a coarse sieve and allow to settle. Identify soluble colors in the solution and insoluble pigments in the sediment. ROASTED COFFEE 3. _Macroscopic Examination--Tentative_ Artificial coffee beans are apparent from their exact regularity of form. Roasted legumes and lumps of chicory, when present in whole roasted coffee, can be picked out and identified microscopically. In the case of ground coffee, sprinkle some of the sample on cold water and stir lightly. Fragments of pure coffee, if not over-roasted, will float; while fragments of chicory, legumes, cereals, etc., will sink immediately, chicory coloring the water a decided brown. In all cases identify the particles that sink by microscopical examination. 4. _Preparation of Sample--Official_ Grind the sample to pass through a sieve having holes 0.5 mm. in diameter and preserve in a tightly stoppered bottle. 5. _Moisture--Tentative_ Dry 5 grams of the sample at 105 deg.--110 deg. C. for 5 hours and subsequent periods of an hour each until constant weight is obtained. The same procedure may be used, drying _in vacuo_ at the temperature of boiling water. In the case of whole coffee, grind rapidly to a coarse powder and weigh at once portions for the determination without sifting and without unnecessary exposure to the air. 6. _Soluble Solids--Tentative_