If the coffee be adulterated with what is called Hambro’ powder (roasted and ground peas, &c., coloured with Venetian red) or roasted corn, we have a further test in iodine, which communicates a purplish or bluish-red tint to the water to which either of these substances has been added. The preceding test is sufficiently delicate and valuable, in all ordinary cases, for detecting chicory in coffee; but to those familiar with microscopic investigations, the microscope furnishes another mode of proceeding: fragments of dotted ducts being found in chicory, but not in pure coffee. They are not met with, however, in great abundance; and some patience and care, therefore, are requisite in searching for them. The starch grains of Hambro’ powder are readily detected by the microscope, as also the blackening effect of a solution of iodine on them. Plate 10 represents the structure and character of genuine ground roasted coffee, and of a fragment of roasted chicory-root, showing the dotted or interrupted spiral vessels which pass in bundles through the central parts of the root, magnified 140 diameters; copied, by permission, from Dr. Hassall’s work on “Food and its Adulterations.” In the raw chicory-root three parts or structures may be distinguished with facility, cells, dotted vessels, and vessels of the latex. These vessels afford useful means of distinguishing chicory from some other roots employed in the adulteration of coffee. The chief part of the root is made up of little utricles or cells. These are generally of a rounded form, but sometimes they are narrow and elongated. The former occur when the pressure is least and the root soft, the latter in the neighbourhood of the vessels.[3] There are four characters by which adulterated chicory may be distinguished from the genuine. 1st. It yields to cold water a much whiter colour. In using this test it is necessary to have a sample of genuine chicory for comparison. 2ndly. A decoction of chicory containing either roasted grain or pulse, yields when cold a purplish or bluish-black colour, with a solution of iodine; whereas a corresponding decoction of genuine chicory is merely coloured brown by iodine. 3rdly. The microscope detects in adulterated chicory the torrefied starch grains of either corn or pulse. That they are starch grains is shown by the action of a solution of iodine, which blackens them. 4thly. The odour and flavour will sometimes detect adulterations. Roasted and ground chicory attracts water from the air, and thereby increases in weight and becomes clammy. The grinders are accustomed to return as much by weight of ground chicory as they receive of the unground root, for the loss which the root suffers by grinding is more than compensated by the absorption of water from the air. THE END. C. WHITING, BEAUFORT HOUSE, STRAND. FOOTNOTES: [1: Mr. J. Crawfurd on the History of Coffee, in the Statistical Society’s Journal, vol. xv. p. 51.]