SHRINKAGE OF CORN IN STORAGE, 7 



was accompanied by a rapid rise in the temperature of the corn and 

 a very marked increase in the rate of shrinkage, as iUustratcd in 

 figure 3. 



During the eight days from April 21 until April 29 the loss in 

 weight was five-tenths of 1 per cent, or one-tenth of 1 per cent more 

 than the loss from January 5 to April 21, the period of 106 days in 

 which the corn remained in good condition. The increase in the 

 average temperature of the corn from April 21 to April 29 was from 

 69.5° F. to 108° F., or 38.5° degrees. The maximum temperature 

 recorded on April 29 was 130° F. at the top of the fourth 100 bushels, 

 as compared with a maximum of 87° F. on April 21. 



Duiing the 15 days immediately following, April 29 to May 14, the 

 shrinl<;age amounted to shghtly more than 2 per cent. The average 

 temperature of the corn on May 14 was 111.3° F. The maximum 

 temperature of the corn on May 14 was 119° F. around thermometer 

 No. 3, as compared with, a maximum of 133° F. two days previous. 

 The decrease in the temperature of the corn at tliis time was due to 

 a reduction in the biochemical changes and to the decreased activities 

 of the organisms responsible for the deterioration, influenced in a 

 measure, perhaps, by the sudden drop in the air temperature. 



The total shrinkage in the corn from January 5 to May 14 was 815 

 pounds, or approximately 3 per cent. The maximum average tem- 

 perature of the corn for any given date, as shown by the four electrical- 

 resistance thermometers, was 127° F. on May 5. The highest tempera- 

 ture recorded was 138° F. on May 2 around thermometer No. 3 at 

 the top of the fourth 100 bushels, as compared with an average 

 temperature of 20° F. at the beginning of the test. 



On May 14 the corn, after it had remained in the hopper of the 

 scale for 129 days without handlmg, was "run out" and elevated 

 three times to the same scale. On the first elevation the loss was 

 205 pounds, or approximately eight-tenths of 1 per cent; on the 

 second elevation the loss was 170 pounds, or approximately six- 

 tenths of 1 per cent; and on the third elevation the loss was 73 

 pounds, or approximately three-tenths of 1 per cent. The total loss 

 during the three elevations was therefore 448 pounds, or 1.6 per 

 cent, on the basis of the original 28,000 pounds, or 1.65 per cent on 

 the basis of the actual weight of corn in the hopper of the scale just 

 previous to "handling." 



The average moisture content of the samples drawn from the com 

 immechately prior to the third elevation was 16.5 per cent, as com- 

 pared with an average moisture content of 18.8 j)er cent when the 

 corn was first placed in the hopper of the scale, while the percentage 

 of sound corn had decreased from 97.1 per cent to 7.6 per cent within 

 the same period of storage. 



[Cir. 81] 



