Page:Foods and their adulteration; origin, manufacture, and composition of food products; description of common adulterations, food standards, and national food laws and regulations (IA foodstheiradulte02wile).pdf/281

 No. 1, and discloses the half-inch opening (half closed by the slide) through which the dough is forced by the pressure of the rod No. 4. The slide by which this opening is closed is plainly shown; also the socket for holding No. 3. No. 3 is a brass tube 3 inches high and 1 inch internal diameter, with a small knob to fit into the notched opening in the side of the socket seen in No. 2, to hold No. 3 firmly in place. No. 4 is a steel rod 15/16 inch in diameter and 12 inches long, with a thin brass cap 1 inch in diameter, beveled slightly so that the front edge fills the barrel of No. 3 without friction, and is yet dough-tight. Near the top the rod is marked into inch spaces.

In using the farinometer two points are considered:

1. The water-absorbing power of a flour, or the percentage of water it will take up to form a dough of a certain consistency.

2. The viscosity of such dough, or its resistance to change of form under a uniform force; e. g., the length of time in seconds required to force a cylinder of dough 1 inch high through a hole one-half inch in diameter under the pressure of a vertical steel rod 13 inches long and weighing 2-1/2 pounds avoirdupois.

——(Bulletin 13, U. S. Dept. of Agriculture.)

Bleaching of Flour.—At the present time flour is extensively bleached for the purpose of making an inferior article resemble a superior one. By this means a greater percentage of the flour produced can be rated as of first quality. Ozone and oxids of nitrogen developed by electrical discharges are the principal bleaching agents employed. Bleached flour should bear a label indicating to the purchaser the character of the manipulation to which it has been subjected.

Adulterations of Flour.—The adulteration of wheat flour is not prac-