Food and its adulterations : comprising the reports of the Analytical sanitary commission of "The Lancet" for the years 1851 to 1854 inclusive, revised and extended being records of the results of some thousands of original microscopical and chemical analyses of the solids and fluids consumed by all classes of the public ... / by Arthur Hill Hassall.

Arthur Hill Hassall

Date:: 1855

Credit: Food and its adulterations : comprising the reports of the Analytical sanitary commission of "The Lancet" for the years 1851 to 1854 inclusive, revised and extended being records of the results of some thousands of original microscopical and chemical analyses of the solids and fluids consumed by all classes of the public ... / by Arthur Hill Hassall. Source: Wellcome Collection.

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decoction. We have not found this to be correct in all cases, for on adding iodine to decoctions of five diilerent coffees ascertained to be adulterated with roasted corn, the li(]uids did not become blue, but almost black, with a tiii{?e of brown or olive. This appears to arise from the obscuration of the blue colour developed by the iodine, by the rich brown colouring matter of the chicory —a proportion of which almost always accompanies tlie adulteration with corn. This test, however, is still very useful, in some cases, although it does not often give rise to a colour which can be called blue. It should be known, also, that solution of iodine, atlded to a cold decoction of chicory root, deepens the colour very greatly, owing probably in part to the presence of a minute quantity of starch : the increase of colour is never, however, so considerable as when flour is present. It is to be further observed that no exact idea can be formed in this way of the quantity of starch contained in the adulterated coffee, because the greater part being charred, gives no reaction with iodine. With these explanations the above tests will be found very useful to those who have not a microscope at command ; but that instrument affords the only ready and certain means of detecting the majority of the adulterations to which ground coffee and other vegetable powders are so subject. In searching for roasted corn in coffee with the microscope, the fragments, before being submitted to the object glass, should be well broken up with the points of needles. We have now considered all the more important adulterations to which, as appears from the preceding analyses, coffee is subjected: it has been stated, how- ever, that the berry is sometimes imitated; but of this no positive evidence has fallen under our own observation. Some grocers make it a practice, in order to give their customers confidence, to grind the coffee while they wait for it. In such cases it is usual to keep a box of chicory nibs of about the size of coffee berries upon the counter; during the grinding a handful or so of the nibs is adroitly transferred to the mill usually without the least suspicion being excited. We shall hereafter have occasion to return more than once to the consideration of the adulteration of coffee. SUGAR, ITS IMPURITIES AND ADULTERATIONS. Two kinds of sugar have been particularly distinguished by chemists — viz., cane and grape sugar, or glucose : the first is obtained from the sugar-cane, the beet- root, the maple tree, and some other plants, — while the second is contained iu greater or less quantities in most fruits, and particularly in grapes and figs. Honey, although usually described as consisting of grape-sugar, contains a large quantity of crystallisable sugar resembling cane-sugar, and is therefore probably a mixture of the two kinds. These two sugars differ considerably in many of their properties. Cane-sugar consists of oxygen, hydrogen, and carbon, in definite proportions ; it is crystal- lisable, the crystals are six-sided oblique prisms, and when pure, not prone to deliquesce, or alter when exposed to moisture or a moderate temperature. Grape-suijar consists of the same elements, but contains a less proportion of carbon. Unlike cane-sugar, its manufacture can be effected by art, that is, by the action of the dilute mineral acids, particularly the sulphuric, on either starch or woody fibre ; it has but little disposition to crystallise ; and when it does so, the crystals assume no definite figure, but are arranged iu acicular tufts; exposed to moisture, or a moderate temperature, it readily deliquesces. Pure and unadulterated cane-sugar, therefore, should present a highly crys- talline texture, should be of light colour, and free from clamminess or moisture. These two sugars may be readily discriminated from each other by the action of certain tests, and grape-sugar particularly by the copper and potassa tests. Now grape-sugar is frequently met with in the brown sugars ot commerce, in considerable quantity, and is sometimes introduced for the purpose of adulteration. This adulteration Dr. Uro, in the Supplement to his Uictionarj' of Arts, Mines, and Manufactures, states, can always be detected by means ot the well-

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