1108 
Journal of Agricultural Research 
Vol. XXVIII, No. 11 
Table II .—Fall in temperature of grain following fumigation with carbon 
disulphid 
BIN No 1 
Tempera¬ 
tures before 
fumigation, 
January 11, 
1922 
Tempera¬ 
tures, 
January 13 
Tempera¬ 
tures, 
January 20 
| 
°jp 
°F. 
°F. 
100 
60 
40 
90 
60 
40 1 
98 
56 
40 j 
94 
56 
40 ! 
71 
50 
40 j 
93 
50 
40 | 
98 
56 
40 1 
98 
58 
40 
BIN No. 2 
i 
S 
°F. 
1 i 
! °F. | 
76 
60 
i 40 
88 
62 
40 | 
82 
58 
40 ! 
91 
60 
I 40 
90 
60 
j 40 
70 
55 
40 
92 
58 
40 
74 
54 
40 ! 
78 
58 
40 ! 
45 
i 
40 
40 | 
It should be recorded that a portion of the grain in the last-mentioned wheat 
was not fumigated, and while the temperature of the fumigated portion dropped 
to 40° F., as noted in Table II, the unfumigated grain continued heating for over 
a month until it was sold by the owner. Samples of wheat taken from this bin 
before fumigation showed the hottest wheat (91° F.) to contain a moisture con¬ 
tent of 15.1 per cent; the cold, unheating wheat a content of 13.9 per cent. After 
fumigation, the grain which had been hottest gave upon analyses a moisture 
content of 14.4 per cent. 
CAUSE OF HEATING IN GRAIN 
Factors causing heating of grain are not well understood. Enzymatic action 
and growth of molds such as Aspergillus are said to be associated with increasing 
temperature when no insects are present. Bailey and Gurjar state (13) in the 
conclusions to their report that the deductions from their investigations ( ‘ support 
the findings of earlier investigations that spontaneous heating in damp grain is 
occasioned by the biological oxidation of dextrose and similar sugars, chiefly in 
the germ or embryo of the kernel.” Dendy and Elkington (14) in 1919 published 
an article on the prevention of heating in wheat by means of air-tight storage, 
basing their work upon the assumption that the heating of the grain is confined 
to those portions to which air has free access, and not taking insects into con¬ 
sideration. The temperature of about 150° F. (53° R.) recalled by Duhamel du 
Monceau and Tillet in 1762 in their report on the Angoumois grain moth must 
have been caused by agencies other than insects, for grain pests are killed by 
temperatures above 125° F. It is believed by some that the heating of grain is 
sometimes started by insects and that their development makes it possible for 
other agencies not so well understood to gain a foothold and carry on the destruc¬ 
tion. In discussing a paper by Doran (7), presented before the Washington 
Entomological Society in 1892, its author expressed the opinion that heating of 
