GLUTEN  , a tough, tenacious, ductile, somewhat elastic, nearly tasteless and greyish-yellow albuminous substance, obtained from the

flour of wheat by washing in water, in which it is insoluble . Gluten, when dried, loses about two-thirds of its weight, becoming brittle and semi-transparent; when strongly heated it crackles and swells, and burns like feather or horn . It is soluble in strong acetic acid, and in caustic alkalis, which latter may be used for the purification of starch in which it is present . When treated with • r to • 2 % solution of hydrochloric acid it swells up, and at length forms a liquid resembling a solution of albumin, and laevorotatory as regards polarized light . Moistened with water and exposed to the air gluten putrefies, and evolves carbon dioxide, hydrogen and sulphuretted hydrogen, and in the end is almost entirely resolved into a liquid, which contains leucin and ammonium phosphate and acetate . On analysis gluten shows a composition of about 53 % of carbon, 7 % of hydrogen, and nitrogen 15 to 18%, besides oxygen, and about r % of sulphur, and a small quantity of inorganic matter . According to H . Ritthausen it is a mixture of glutencasein (i.iebig's vegetable fibrin), glutenfibrin, gliadin (Pflanzenleim), glutin or vegetable gelatin, and mucedin, which are all closely allied to one another in chemical composition . It is the gliadin which confers upon gluten its capacity of cohering to form elastic masses, and of separating readily from associated starch . In the so-called gluten of the flour of barley, rye and maize, this "body is absent (H . Ritthausen and U . Kreusler) .

The gluten yielded by wheat which has undergone

fermentation or has begun to 'sprout is devoid of toughness and elasticity . These qualities can be restored to it by kneading with salt; lime-water or alum . Gluten is employed in the manufacture of gluten bread and biscuits for the diabetic, and of chocolate, and also in the adulteration of tea and coffee . For making bread it must be used fresh, as otherwise it decomposes, and does not knead well . Granulated gluten is a kind of vermicelli, made in some starch manufactories by mixing fresh gluten with twice its weight of flour, and granulating by means of a cylinder and contained stirrer, each armed with spikes, and revolving in opposite directions . The process is.completed by the drying and sifting of the granules .