Food may be adulterated cither by the fraudulent substitutes of cheaper foods, or by the addition of substances which have a deleterious action. The objects arrived at by the manufacturer who engages in this malpractice are - (1) to increase the bulk of the food; (2) to give an erroneous impression as to the strength of the food; and (3) to alter the appearance in a manner favourable to the manufacturer. An instructive table illustrating the extent to which adulteration of food was practised in America prior to the passing of the Pure Foods Act is given by Thompson as follows. This shows that about 40 per cent, of foodstuffs were adulterated. The forms in which food may be adulterated are legion. As common examples, mention may be made of wheat flour with bran, milk with water and sugar, powdered sugar with barium sulphate, honey with glucose, coffee with sugar and caramel, oleo-margarine as butter, pickles with copper and iron; wines and liquors with hematoxylin, alum, and other salts; olive oil with cotton-seed oil. The adulteration of flour by bleaching is fully dealt with on p. 90.

Table Illustrating Adulteration Of Foods