Flour
A name given in a general way to all the finer descriptions of pulverized grain or peas, which when unfit for food finds its way into the foundry, to be there employed for mixing with sands, blackings, and facings in order to impart artificial strength to those substances by binding the particles together with the gluten it contains. The gluten of wheat-flour is extremely tenacious and elastic; the value of flour as a toughener of sand depends upon this substance, which, when dried, has a birdlime or glue-like aspect which imparts a fibrous, tough, and elastic quality to sands which would otherwise be lacking in these important essentials. This, of course, admits the use of sands absolutely free from alumina, being by this artificial stiffening made to perform duties that would be possible only with sands containing alumina in considerable proportions. Alumina hardens in the core when cast, and is difficult to remove; gluten burns away, leaving the sand free. See CORE-SAND; CORE-COMPOUND; MOLASSES; GLUE; GLUTEN; STARCH.