DESCRIPTION OF PLATES. 



Plate I. Air-bath used for determining the amount of moisture in a sample of corn, 

 with aluminum pans and electric heater inside. A piece of asbestos is placed 

 over the heater to distribute the heat more evenly to the pans. The forceps 

 shown below are for transferring the pans to and from the bath to avoid the 

 possible error consequent on touching them with moist hands. 



Plate II. Fig. 1. — Mill for grinding corn samples, with extra set of burrs and brush 

 for cleaning mill after each grinding. This mill may be clamped to the edge of 

 a table and is simple and strong. It may be easily taken apart for cleaning or 

 changing the burrs. Fig. 2. — Balance used for weighing corn samples. This 

 1 lalance is surrounded by a metal frame set with plate glass, and is provided 

 with a sliding weight on a fixed scale, so that the weighing may be done rapidly. 



Plate III. Kernels of corn shown in longitudinal and cross section. Magnified six 

 times. These kernels show rather extreme variations in texture. The two ker- 

 nels ut the left of the picture show a high proportion of the hard or translucent 

 substance of the kernel outside the germ, which has been shown by Professor 

 Hopkins, of the Illinois State Experiment Station, to be directly correlated with 

 high protein content. The kernels on the right show a relatively small amount 

 of this hard substance, and are consequently of the type which is low in protein 

 and therefore rich in starch. For processes of manufacture of corn where a 

 granular product is desired the type of corn shown on the left is much preferred, 

 while for starch manufacture the type shown on the right of the picture is more 

 desirable. In the same way the relative size of the germ of the corn kernel 

 indicates the percentage of oil contained, since practically all the oil of the corn 

 kernel is found in the germ. 



Plate IV. Kernels of corn showing various kinds of damage, and sound kernels 

 shown for comparison. Twice natural size. The upper three rows are of ker- 

 nels showing the various mold growths commonly found on damaged corn. 

 These molds develop only on excessively moist corn and are much more likely 

 to occur when there is a deposit of fine meal or dirt in the germ indentation. 

 This deposit offers a good culture medium for the development of the molds, 

 and in a majority of cases the damage starts at that point. Perfectly clean corn 

 will carry or store much more safely than dirty corn having the same amount of 

 moisture. 

 24 







