FIELD CROPS 385 



was approximately four-tenths of 1 per cent. The shrinkage in 

 weight from April 21 to May 14 was approximately 2.6 per cent, 

 during which time the corn went out of condition, becoming sour 

 and hot, with a maximum temperature of 138 F. on May 2. The 

 shrinkage during the three elevations on May 14 was 448 pounds, 

 or 1.65 per cent, on the basis of the actual weight of corn in the hop- 

 per of the scale just previous to handling. The shrinkage during 

 storage from May 14 to June 1, after the corn was cooled to 55 F. 

 by handling, was 2.6 per cent. The total shrinkage during the test 

 was 1,970 pounds, or slightly more than 7 per cent, while the natural 

 shrinkage exclusive of the loss during the three elevations was 1,522 

 pounds, or approximately 5.6 per cent, calculated on the actual 

 weight after making deductions for samples drawn for analyses. 

 The rate of shrinkage while the corn remained in good condition 

 was largely influenced by the weather conditions and by the relative 

 humidity and temperature of the atmosphere. (B. P. I. Cir. 81, 

 1911.) ' 



Wheat fluctuates in weight according to the dry ness of the air. 

 The extent of this variation, under ordinary conditions, does not ex- 

 ceed six per cent, but where the grain is taken from an intensely dry 

 climate to a comparatively damp one the gain may amount to twenty- 

 five per cent. 



In 1893, a firm of millers of North Lansing, Michigan, bought 

 1,500 bushels of wheat which was then in a hard, dry condition. It 

 was hauled as soon as threshed and placed in the elevator. Ten days 

 thereafter it was removed and found to have shrunk a little over 

 thirty bushels. A loss of two per cent. Again, in 1896, 900 bushels 

 placed in the same elevator while still slightly damp shrank thirty 

 bushels in four months. A loss of three and one-third per cent. 



An experiment was performed under the supervision of Profes- 

 sor Hilgard of the University of California to test the actual amount 

 of gain or loss in weight in stored grain due to the fluctuations in 

 the moisture content of the air. The results were as follows: 



The dried grain was spread out in a very thin layer upon a small 

 table, standing in shallow water and covered with a bell-jar. To 

 make the air within this space as nearly saturated as possible, filter 

 paper, dipping into the water below, extended near the grain, but not 

 touching it. The whole was kept at a temperature of about 64.4 

 degrees F., and the grain was weighed from time to time in a corked 

 flask to prevent loss during the weighing. Under such circumstances 

 grain would continue to absorb moisture and increase in weight from 

 twelve to eighteen days, the absorption being accompanied by an in- 

 crease of bulk, which was not measured. The gain in weight from 

 such absorption was as follows: In 18 days oats gained 19.8 per 

 cent, barley 20.4 per cent, and in 14 days wheat gained 18.8 per cent. 

 In all cases the increase was very rapid at first, then slower and 

 slower, until about the 13th or 14th day, when a sudden increase oc- 

 curred, due to the development of mold caused by the great amount 

 of moisture present. Nearly half of the total increase occurred in 

 the first twenty-four hours. 



