BLEACHING OF OATS WITH SULPHUR DIOXID. 
grain can be shipped with safety. Some operators prefer to. add 
as little moisture as possible, in which case the product merely 
requires cooling before shipment. Others maintain that they get 
a better-appearing product by adding considerable moisture, and 
then drying out the excess before shipment. 
The bleaching of oats and barley as practiced at the present time 
is a continuous process after the apparatus has once been set in 
motion, and very little attention is required except to see that the 
proper supply of sulphur is kept in the furnace, the proper amount 
of water is added, and that the grain is kept at a uniform flow. 
Some of the largest and most efficient bleaching plants have capac- 
ities of 2,000 bushels of grain per hour. 
Photographs of sulphur-bleaching apparatus 
are shown in figures 1, 2, and 3, which illus- 
trate some of the leading types of commercial 
bleachers. 
CHARACTER OF INVESTIGATIONS. 
In the fall of 1915, samples of oats were 
collected from representative sections in 
which the commercial bleaching of oats is 
practiced to a considerable extent, and these 
samples were carefully examined and ana- 
lyzed. The analyses of samples from the 
same lots of grain before and after bleaching 
were compared. Using these data as a basis 
for further investigations, additional experi- 
ments were undertaken. Visits were made 
to some of the most important elevators 
throughout the Middle West that operate 
bleachers. Samples of as many different 
grades and qualities of oats as possible were 
obtained and studied. These were bleached 
by the regular process in vogue at the ele- 
vator, and also by modifications of this method which suggested 
themselves to the writer or were suggested by the operator of the 
elevator. Careful attention was paid to the amount of water 
absorbed, the atmospheric conditions, and the condition and 
appearance of the oats before and after bleaching. An endeavor 
was made at all times to improve if possible the appearance of the 
final product. 
Each different grade or quality was carefully studied before and 
after treatment, and as many types of damaged oats as possible 
were obtained and examined. The effect of bleaching on each kind 
Fig. 1.— A modern grain bleacher. 
