34 FLOURS. 



(24) Rice Flour. 



In the rice flour of commerce there is only a very small proportion 

 of the seed-coats of the grain, and the chief characters are there- 

 fore to be found in the size and shape of the grains of starch of 

 which it almost entirely consists. These are as follows : (1) Small 

 simple polyhedral grains. (2) Large or small compound grains, 

 oval or rounded in shape, and varying in size according to the 

 number of constituent grains. (3) Fragments of the above of vary- 

 ing shape. (4) Masses of starch from the cells of the endosperm, 

 or masses of several cells together. 



The vegetable debris to be found in rice flour are only a few 

 very narrow tubular cells closely attached to a layer of very small 

 elongated cells. A knowledge of these characters is very desirable 

 as the adulteration of wheat flour with rice flour is frequent at 

 times. 



