4 BULLETIN" 570, TJ. S. DEPARTMENT OF AGRICULTURE. 
rounded by a sieve mantel of heavy iron wire. The rice is fed from 
the top and is rubbed thoroughly between the cone and the sieve 
before passing out at the bottom. The severity of the scouring 
may be varied by raising or lowering the cone, thus decreasing or 
increasing its distance from the wire screen. One or two of these 
pearling cones are used in addition to one or two sets of hullers. 
The product taken off by the pearling cone is generally known as 
" pearling-cone meal" and may be sold as such, although some 
mills make a practice of mixing this product either with their bran 
or polish, as demand or price may dictate. 
Brush. — During the milling in the hullers and pearling cone the 
rice becomes very warm, and, hence, before further treatment it 
is run to large cooling bins where it is allowed to remain for several 
hours. A further reason for collecting the grain in bins at this 
point lies in the fact that a uniform flow of rice to the brush is 
necessary for good milling, and the brush handles rice much more 
rapidly than the hullers or pearling cone. It is therefore necessary 
to store the rice from the hullers and pearling cone until such an 
amount has been partly milled that a uniform feed for the brush 
machine is assured before it is started. From these bins the rice, 
which is now practically white in color, but is more or less rough 
and unsightly in appearance, is conveyed to the brush to remove 
more of the inner bran coat and to give the rice a smoother finish. 
The brush consists of a vertical cylindrical frame covered with a 
thick padding of soft leather strips. This frame revolves at a high 
rate of speed within a cylinder of wire screen. The rice enters at 
the top of the brush and is rubbed smooth by friction with the brush 
and screen while passing to the bottom of the machine. A con- 
siderable amount of heat develops in the brush, and it is found 
necessary to cool the brush by passing a stream of air upward through 
it. This air current carries with it a small amount of polish which 
is recovered in dust collectors. The material which passes through 
the screen of the brush, mixed with the small amount of material 
from the dust collectors, constitutes the rice polish usually found on 
the market. The rice leaving the brush machine is suitable for 
market, although, as a rule, it is separated into different grades by 
a system of screens or graders, and in many cases is given a high 
finish by the use of a small amount of glucose and talc. 
A graphic diagram of the mill process is shown in figure 1. 
ANALYSIS OF RICE AND ITS BY-PRODUCTS. 
With a few minor variations the process just described is followed 
in all rice mills. It results in three by-products, namely, rice hulls; 
a rice bran, consisting of a mixture of the stone-reel, first-huller, and 
second-huller brans; and rice polish. 
