TREATMENTS OF SEED WHEAT FOR LOOSE SMUT 
17 
than from the modified treatment. It appears, however, that the 
former would be considerably more difficult to apply than the modified 
treatment. In this regard it was suggested that the single-bath 
method might be applied with considerable facility to small batches 
by placing half -filled sacks of wheat on racks which could be lowered 
into and raised out of a large tank containing water which was me- 
chanically agitated and maintained at a constant temperature. 
In order to determine whether agitation of the water could be sub- 
stituted for that of the sacks, an experimental tank was constructed, 
as shown in Figure 3. There were two racks, one being shown sus- 
pended in the plate, each having a capacity of six sacks of wh#at. 
The racks could be raised or lowered by means of chain blocks. 
In the latter position they came to rest side by side, with the bottom 
tray of each rack directly over a spiral agitator. The agitators were 
9 inches in diameter and extended throughout the length of the tank. 
In the studies of heat penetration the spirals were revolved at a speed 
which caused a very vigorous agitation and a uniform distribution of 
temperature throughout the water. The temperature was main- 
tained by a thermostatic device which injected steam into the 
water wlien necessary. Burlap sacks and the more tightly woven 
seamless cotton or mill sacks of 2-bushel capacity were employed 
in the experiments. They were half filled with wheat, tied at the 
top to provide ample room for the swelling of the grain, and laid on 
one side. Two sacks were placed on each of the trays. The bulb of a 
long-stemmed thermometer was carefully forced through the side of 
the sack under observation and inserted in the center of the mass 
of grain. The rack was then lowered into the water, which was agi- 
tated and maintained at 48° C. Tests were made with sacks placed 
on a bottom tray directly over the agitator, on a top tray, and with 
one or both agitators active. The temperatures registered were 
recorded at intervals of five minutes, and the tests were discon- 
tinued after the temperature in the mass of grain reached 48° C. 
The results are presented in Table 10. 
Table 10. — Time necessary to raise the temperatures of lots of wheat in burlap 
and in cotton sacks to 4$° C. when immersed in water maintained at 48° C. 
[The sacks were placed on racks at different distances from one or two active agitators] 
Test sack 
Location 
Num- 
Temperature (° C.) in center of sacked wheat mass after the 
number of minutes specified 
Kind 
Dis- 
tance 
from 
agita- 
tor 
ber of 
agita- 
tors 
active 
5 
6 10 15 
20 
22 
25 
30 
35 
38 
Cotton.. 
Bottom tray. 
do 
Top tray 
Inches 
4.5 
2 
36.9 
47.5 
34.0 
41.7 45.8 
48.0 
47.7 
48.0 
Burlap. . 
4.5 2 
Do.... 
. 22.5 
1 
42.8 43. !> 
45.0 
46.0 
46.8 
47.6 
48.0 
Table 10 shows (1) that the time required for penetration of heat 
through a burlap sack was approximately one-fourth that required for 
a cotton sack, (2) that in Durlap sacks rapid penetration occurred 
only when the sack was very close to the agitators, and (3) that reduc- 
tion of agitation and increase of distance from the source of agitation 
