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,itiB.««4i '.vi'iaTra. av-:vteJi;,-x-'"S'Si«,.'fLj 

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Th.«, mutilolion, ond underlining of books 
oro reoions (or disciplinary atlion ond moy 
resiill in dlsmlssol Iron, tiro University. 

MAY \ 




EB 1 1 1975 

loEc 4 m 

L161 — O-1096 

THE LlBRftRY Of Ti'-i: 
FEB ;i* 1930 




Assistant Curator of Economic Botany 

Leaflet 14 





No. 1. Figs $ .10 

No. 2. The Coco Palm 10 

No. 3. Wheat 10 

No. 4. Cacao 10 

No. 5. A Fossil Flower 10 

No. 6. The Cannon Ball Tree 10 

No. 7. Spring Wild Flowers 25 

No. 8. Spring and Early Summer Wild Flowers . . .25 

No. 9. Summer Wild Flowers 25 

No. 10. Autumn Flowers and Fruits 25 

No. 11. Common Trees 25 

No. 12. Poison Ivy 25 

No. 13. Sugar and Sugar- Making 50 

No. 14. Indian Com 25 





u.N!v:.'^siTy OF Illinois 

Courtesy of Indiava Faryner's Guide 


Field Museum of Natural History 

Chicago, 1930 

Leaflet Number 14 
Copyright 1930 by Field Museum of Natural History 

Indian Corn 



Origin, Geographic Distribution and Varieties 2 

] Use by the American Indian 14 

Modern Industrial and Experimental Products 19 



THE imm Of THE 

FEB 2 * 1930 



Origin. — When the white man reached America he 
found com cultivated by the Indians in many widely 
separated areas. Its history before that time remains 
mostly a matter of conjecture. The numerous Indian 
myths fail to throw much light on the subject, but testify 
to the importance and antiquity of corn on this continent. 
Every Indian myth that attempts to explain the origin 
of agriculture deals with corn. Among the Quiche of Guate- 
mala tradition relates that certain gods or godlike men, 
recently arrived in the land and much displeased with 
living conditions, planned to reclaim the natives from 
barbarism. After mature deliberation, four barbarian 
chiefs were sent to a distant land to get new ideas. They 
returned bringing with them the "ears of yellow maize 
and white," which rounded out their scheme of existence 
and became their chief reliance for food. Another tradi- 
tion of the Quiche makes com the very breath of life. 
Made of earth, man was without life; but by means of 
maize he was converted into flesh and blood. 

In an account of the South American Canari tribe, 
two brothers escaped the Deluge by climbing a mountain 
in Ecuador. When the waters subsided, they descended 
in search of food. Two parrots repeatedly visited the 
famishing men, giving them food and drink made of 
maize. One of the birds was captured, whereupon she 
miraculously changed herself into a beautiful woman. 
She gave the men the seed of maize, taught them its 
culture and uses, and ultimately became the ancestress 
of the Canari race. 

The Navajos say that they first knew of com when 
a turkey hen came flying from the direction of the morn- 
ing star and shook from her feathers an ear of blue com. 



Indian Corn 

In a tradition of one tribe of the United States, the 
Great Spirit comes to earth in the form of a woman and 
falls asleep. On waking, she arises and walks through 
the land, while useful plants spring up around her. At 
the right and left grow pumpkins and beans, and from 
her footprints comes maize. 

Upon the return of his first expedition in 1492, 
Columbus reported the growing of maize in Cuba. Alvar 
Nufiez (Cabeza de Vaca) described it as planted by 
Indians in Texas in 1527. Cartier in 1534 found it in 
Canada, and in 1585 Hariot gave a good description of 
it on Roanoke Island, while in 1607 Captain John Smith 
wrote of it around Jamestown. 

Charred com has been found in the remains of the 
Mound Builders of Ohio and the Mississippi valley. 
Dried com has been found in the pueblos of the south- 
west and in the burials of Peru. At Tarapaca, Chile, 
corncobs have been found buried beneath an ancient 
lava flow. Darwin found, on the coast of Peru, ears of 
com together with eighteen species of recent seashells, 
imbedded in a beach which had been raised to at least 
eighty-five feet above the level of the sea, through move- 
ment of the earth, and this com was identical with that 
taken from old Peruvian tombs. A petrified ear of com 
was found at Cuzco, Peru. These findings place the 
cultivation of this plant in America at an early date. 

By botanists com is considered to be a highly 
specialized cultivated grass. For centuries it has been 
dependent upon man, not only for improvement, but 
for the continuation of life itself. As a result, com at 
present exists in a form which it did not have before 
the coming of the Indian to the New World. 

Com is thought to have originated either in the 
western mountains of South America or in Mexico or 
Central America. Wild plants very closely related to 
com have been found only in America — on the table- 


Original in Field Museum 


Indian Corn 5 

lands and in the foothills of Central America and south- 
eastern Mexico. One of these plants, teosinte (Euchlaena), 
hybridizes with com. This has led those who have 
studied plants to believe that com originated there. 

As corn was one of the chief foods of the Indians, 
it is not strange that it played a decorative part in 
their pottery and sculpture. It also played a part in their 
religion and so is found the com altar of the American 
Indian — the six-direction altar. Six ears of com were 
placed on the ground as follows: yellow pointing north, 
blue pointing west, red pointing south, white pointing 
east, black pointing northeast, indicating above, and 
sweet com pointing southwest, indicating below. Corn 
was used in many other ceremonies. The Aztec god of 
agriculture is sometimes represented with a stalk of 
com in one hand. Centeotl was the Ceres of the Aztecs, 
their goddess of com. The Mayas and Peruvians also 
made extensive use of corn in their festivities. 

United States. — Com is the outstanding crop of the 
United States, both as to value and acreage. In both 
value and area it exceeds the combined crops of wheat, 
oats, rye, barley, buckwheat, rice, fruits, and nuts. Since 
the first official registration in the United States, in 1840, 
of the number of agricultural products and their value, 
corn has led all other cereals in importance, and since 
1865 there has been a noticeable increase in production 
in proportion to the population. 

Although corn may be grown under widely varied 
climatic conditions, the best results are obtained only 
within limited areas. In the United States the best com 
is grown in those parts of the country which have an 
average summer temperature of seventy to eighty degrees, 
an average night temperature of over fifty-eight degrees, 
a frost-free season of at least 140 days, and a yearly 


6 Field Museum of Natural History 

rainfall of twenty-five to fifty inches, of which seven to 
eight inches fall in July and August. The soils best 
suited to corn are dark, fertile loams or silty areas, well 
supplied with heat and moisture, and well drained. 

Thus the ideal conditions for extensive corn production 
occur only in a few parts of the world, and are found to 
the greatest extent in the United States. Within such 
areas the corn crop reduces the production of other 
cereals, especially those which must be grown during the 
same season of the year, to a negligible position, since 
com yields about twice as much grain and, with the 
fodder, more than three times as much food per acre as 
either wheat or oats. 

The United States produces about three-fourths of 
all the corn in the world. Although the exact temperature, 
soil, and moisture conditions described above are found 
only in certain parts of the country, corn of one or another 
variety is grown to a greater or less extent practically 
throughout the entire United States. The Mississippi 
valley is the great com country, producing three-fourths 
of all the corn grown within our boundaries. Within the 
Mississippi valley are two centers of maximum com 
production, one in central Illinois and the other including 
western Iowa and eastern Nebraska. In 1909, the area 
devoted to corn-growing in Illinois comprised 10,046,000 
acres, or 10 per cent of all the land given to com pro- 
duction throughout the country. In Iowa were 9,229,000 
acres of com; in Kansas, 8,109,000 acres; in Nebraska, 
7,226,000 acres; in Missouri, 7,114,000 acres; and in 
Indiana, 4,901,000 acres. The corn acreage of these six 
states combined was 47 per cent of the total for the 
country, and their com production 57 per cent of the 
total. As an effect of this large-scale production, a 
system of live stock farming has developed which makes 


Indian Corn 7 

use of com products. One-third of the beef cattle and 
about one-half of the swine in the country are raised in 
these states. 

Although a large percentage of the total crop is 
produced in these middle and western portions of the 
country, com is grown in almost the entire eastern part 
of the United States. Moreover in certain eastern regions, 
the acreage devoted to com, in relation to the total 
acreage given to crops, is greater than anywhere else, 
although the actual acreage and production are small. 
In mountainous eastern Kentucky, where the rural 
population depends for its livelihood largely upon the 
cultivation of small fields of com, 75 per cent of all the 
land under cultivation is given to this product. In 
Florida, southern Alabama, and Mississippi, where the 
land is still largely covered by forests, com occupies 50 
per cent of such land as is sown in crops. 

In spite of the fact that com is the main source of 
food supply in the United States, outside of the southern 
states very little of the com produced is directly con- 
sumed by man. Most of the crop is used in feeding 
live stock, and may be said to be ultimately consumed 
by man in the form of beef, a pound of which represents 
the consumption of ten or twelve pounds of com, or as 
pork, a pound of which requires, in its production, five 
or six pounds of com. A large percentage of the com 
produced in the Illinois and Iowa "com belts" is shipped 
to near-by industrial centers, particularly Chicago, to be 
converted into starch, glucose, and com meal. Some 
of the com is exported in its natural state, but by far 
the greater portion of the crop is fed to animals, and 
reaches the market in that less perishable form. In the 
South, however, practically all the com is consumed at 
home, in the various forms of "hog, hominy, and hoecake." 

Europe. — The production of com is also carried on in 
Europe, in such territories as possess climatic conditions 


8 Field Museum of Natural History 

favorable to this pursuit. Europe as a whole produces 
about one-fourth as much com as the United States. 
The chief corn-growing countries are Hungary, Roumania, 
southern Russia, and Italy, all of which, as to soil, rain- 
fall, and temperature, have similar conditions to those 
in the com belts of the United States. Among these 
nations, Hungary leads in acreage and production. In 
Roumania, however, corn plays a more important part 
in the industrial life of the nation, since it is a main 
source of food and also one of the chief exports of that 
country. Forty per cent of the cultivated land is here 
sown in com, and Roumania produces about four times 
as much corn, in relation to her population, as does 
Hungary. In Russia, most of the com is grown in Bessa- 
rabia, not only because of the favorable climatic condi- 
tions found there, but also because of convenient location 
for shipping. Fifty per cent of Russian com is shipped 
to other countries, while Roumania exports about 40 per 
cent of her total crop. 

Smaller contributors to the European corn supply are 
Italy, where com is grown principally in the valley of 
the Po, and where irrigation is often necessary; France, 
whose small quota is produced partly in the north and 
partly along the Mediterranean coast; and Spain and 
Portugal, where the grain can be grown only along the 
western and northern coasts. 

Egypt and India. — The Egyptian corn crop is produced 
altogether by means of irrigation. The grain is planted 
in July, irrigated about every ten days, and harvested 
in October and November. India has considerable corn 
acreage, although it occupies only about 3 per cent of 
the land under cultivation. Here com is grown in the 
silty soil along the Ganges, and by irrigation in the 
region of the Punjab. It is used principally for human food. 


Indian Corn 9 

Mexico. — Although Mexico ranks second only to the 
United States in the percentage of cultivated land given 
to the production of com, the yield in that country, due 
to primitive agricultural methods, is relatively small. 
Most of the com is grown by peons on the small patches 
which they lease from the owners of large ranches. Irriga- 
tion is often used. A great part of the crop is used for 
the making of com bread (tortillas) which is a favorite 
article of food in Mexico. The com lands are situated 
in the southern part of the country, on the high table- 
lands, and in Yucatan. In spite of the extensive acreage, 
and although very little com is exported from Mexico, 
the native crop is insufficient to supply the needs of the 
country, which regularly imports about one million bushels 
annually from the United States. 

Canada. — In Canada, com is grown chiefly in Ontario, 
under climatic conditions very similar to those found in 
the northern states. Most of the yield is used for silage, 
or fed, fresh from the field, to the farm animals. 

Argentina. — Argentina ranks second to the United 
States in the production of com per capita of the popula- 
tion. Corn-growing here is centered in Buenos Aires, 
Santa F^, and Cordoba, where the mild climate and the 
ishght variability in temperature form very favorable 
conditions for a large yield. Twenty-one per cent of the 
cultivated land in Argentina is sown in com, and this 
percentage shows a tendency to increase. The com is 
planted from September to December. The average 
summer temperature is seventy-five degrees, and the 
annual rainfall of thirty to forty inches contributes to 
the success of the industry, although the greater part of 
the rain comes rather late in the com season. Because 
of the small population, much of the com is exported, 
and the flinty type grown in this section is particularly 
adapted for transportation without great loss. In 1912, 
Argentina exported 64 per cent of her total crop. 



Indian Corn 11 

Varieties of Corn. — Almost fifty years ago Dr. Sturte- 
vant divided Indian com into seven groups, each of 
which has well-developed and lasting characteristics: 
pod corn (Zea tunicata), pop com (Zea everta), flint com 
(Zea indurata), dent com (Zea indentata) , soft corn 
(Zea amylacea) , starchy-sweet com (Zeaamyleasaccharata), 
and sweet com (Zea saccharata) . 

1. Pod corn. — In this group each kernel is inclosed in 
a pod or small husk and the ear thus formed is inclosed 
in a large husk. This type is considered by some to be 
the original type of corn. 

2. Pop corn. — This species group is characterized by 
the large proportion of a tough, homy substance (corneous 
endosperm) in the starchy portion of the kernels, and by 
the small size both of the kernels and of the ear. The 
best varieties for popping have the homy substance 
throughout the starchy portion of the kernels. The 
property of popping, which is the complete eversion or 
turning inside out of the kernel, is caused by the explosion 
of the contained moisture through the application of heat. 

3. Flint corn. — A species group readily recognized by 
having the starchy portion of the kernels inclosed by a 
coating of a horny substance, as shown in a split com 
seed. This homy portion varies in thickness with the 
varieties. It cannot be confused with any other species 
except the pop corn, from which it is set apart by the 
larger kernel and inability to pop. In drying there is 
no shrinkage of the top of the grain and no dent forms. 

4. Dent corn. — A species group recognized by the 
presence of homy substance at the sides of the kernel, 
the starchy portion extending to the summit. By the 
drying and shrinkage of the starchy matter the summit 
of the kernel is drawn in or together, and indented in 
various forms. In different varieties the horny substance 
varies in height and thickness, thus determining the 
character of the indented surface. 





Indian Corn 13 

5. Soft corn. — This species group is at once recognized 
by the total absence of horny material. Due to the uni- 
formity of the shrinkage in ripening, there is usually no 
indentation; yet in some varieties an indentation may 
more or less frequently appear, but on splitting the kernel 
the soft com may always be recognized. 

6. Starchy-sweet corn. — A well-defined species group 
characterized by the translucent, homy appearance of 
the kernels, and their more or less wrinkled or shriveled 

7. Sweet corn. — A well-defined species group char- 
acterized by the translucent, homy appearance of the 
kernels and their more or less crinkled, wrinkled, or 
shriveled condition. 

All seven of these groups of com were grown by the 
Indians of North and South America. The certainty of 
sprouting is highest in pop and flint corns, lower in 
sweet corn, and poorest in dent corn, and the decrease in 
the starchy content of the kernels is in this order: pop, 
flint, dent, soft, starchy-sweet, and sweet. 

At the present time, pop com is extensively grown in 
the United States for that purpose. Almost all of the 
field corn in the United States is of the dent type. Flint 
requires a smaller number of days to mature a crop, and 
is consequently more used farther north and at higher 
elevations above sea level. It is the common field com 
in New England. Dent and flint furnish all the grain of 
commerce and practically all the fodder and ensilage. 
Sweet corn forms the basis of a large canning industry 
in the North Atlantic and North Central states. It is 
less generally grown in the Southern states. Soft corn 
was preferred by the Indians because of its ease of grinding. 



Stalks, Leaves, and Husks. — The Indians commonly 
wasted the stalks, leaves, and husks except for a limited 
use in mats, beds, thatching, and fuel. In Mexico and 
parts of South America the large, outer husks were and 
are still used for wrapping tamales for cooking. The thin, 
inner husks were used for cigarette paper. Like its near 
relative, sugar cane, cornstalks produce sugar. Prescott 
writes of the Aztecs obtaining juice from the stem, which 
was boiled down to a syrup or fermented and used as a 

Ears and Kernels. — The roasting ear was everywhere 
a favorite food of the Indian. Com was eaten raw, 
boiled, or roasted, and the Indian invented the mixture 
of green corn and beans known as succotash. Parched 
com was widely known and used in many ways. 

Meal. — Several different methods were used by the 
Indians in making corn meal. In Pennsylvania, a vessel 
containing sand was heated. The corn was then mixed 
with this sand and slowly heated until the grain burst. 
The burst grain was then taken out and ground to a 
fine powder. In another method the .corn was first par- 
boiled, the water drained off, and the grain dried. The 
dried kernels were roasted on a plate, ashes being mixed 
with them to prevent burning. The grains were stirred 
constantly and soon acquired a red color, at which time 
they were removed and well rubbed. They were then 
mixed with the ashes of the dried stalk of the kidney 
bean, a little water was added, and the mixture thoroughly 
pounded into meal. Among the Indians of the south- 
western United States, the blue com was used. This 
when rubbed in a stone mortar gave a meal of bluish-gray 
color. A second method used in this same section of the 


Indian Corn 15 

country was to cook the com in limewater until the hard 
covering was removed; then the grain was pounded into 
white flour. This last method is used by the white man 
in preparing hominy. 

The food use of corn meal varied in different parts 
of the country. The various ways of making bread were 
as follows: in the neighborhood of Pennsylvania the 
meal was kneaded with water into dough. This dough 
was made into round cakes about six inches in diameter 
and about an inch thick. They were then baked in clean 
wood ashes. Dough was sometimes mixed with pieces of 
pumpkin, beans, chestnuts, huckleberries, etc. Indians 
also mixed smoked eels and shellfish, chopped fine, with 
their corn meal in the making of bread. 

The mestizas of Mexico made similar corn bread in 
various shapes and sizes, known as gorditas. In the 
southwestern United States and Mexico thinner cakes 
called tortillas were also made. In their manufacture a 
thin batter was used, dipped from a bowl by the hands 
and spread in a thin layer on a hot stone or plate. The 
mass quickly puffs up, a sign that one side is done, and 
it is then turned over, while the second cake is placed 
on to bake. Thinner cakes were made of blue starch 
com by the Hopi Indians in Arizona. These thin cakes 
were rolled up like thin jelly rolls and were known as 
piki bread. 

Pinole was corn meal cooked or mixed with sugar from 
the mesquite (Prosopis juliflora D.C) or other source. The 
Central American Indians added a red coloring matter, 
arnatto, to this mixture and called it yixte. In Mexico 
such a mixture without coloring matter was cooked and 
wrapped in small pieces of corn husk, in the form of a 
necklace, for ease of transportation when traveling. These 
were known as saules. 

Various forms of pottage in which corn meal was the 
basis were familiar to the Indian. In the northeastern 



V**'*.** '.* ' •••'•^»**'«»*.»', • • • '^•v*'''*J'^.* *-*•,'-'* *'^ 

Codex Fejervdry — Mayer, pp. 31,-33 


Illustration of maize from a preconquest Indian codex from southern 
Mexico representing the story of the corn plant from planting to harvest. 
The figures read from right to left, the upper row being an allegorical 
series of figures representing corn in its several stages. In the first 
sketch of the series the corn plant is small, scantily clothed and bent 
(immature), while in the third sketch it is larger, fully clothed and 
erect (mature). Along with the corn plant are shown the rain goddess, 

_g6;^^uAq ft (D » A 


^i^ft § % 

flower goddess, and the chief rain god. These were agricultural deities, 
who protected the maize crop. In the left top panel are shown various 
birds and rodents, which destroy the young plants. The lower row rep- 
resents important Mexican divinities. According to J. Eric Thompson 
the time interval between each of the upper series of illustrations is 
65 days. The four intervals together make 260 days, the "tonalamatl" 
or sacred year of the Aztecs and other Central American peoples, used 
in divination and for regulating times for sowing crops, etc. 


18 Field Museum of Natural History 

section of the country the meal was boiled with fresh or 
dried meat (the latter pounded), dried pumpkins, beans, 
or chestnuts. Sometimes the mixture was sweetened with 
maple syrup or sugar. An appetizing dish was made by 
boiling well-pounded hickory nut kernels with corn. In 
the southwestern United States and in Mexico meal was 
often cpoked with pieces of meat with red or green peppers 
or other vegetable. When this is wrapped in corn husks 
and boiled it is known as a tamale. Bread was also made 
from crushed, fresh, undried corn. 

Beverages. — Although the Indians realized the sub- 
stantial way that corn supplied some of their essential 
needs, yet their keenest sense of pleasure came from the 
drinks that it afforded. They had a great many of these. 
One god is said to have given the Mexicans nine excellent 
recipes at one visit. Probably the most commonly used 
fermented drink was chicha, which was widely known in 
many forms. There were many ways of preparing it. 
The dry, parched, or sprouted com was either ground 
or masticated and then mixed with water and allowed 
to ferment. This was highly intoxicating. 



Like the Indian, the white man still makes meal from 
the com kernels, but many other substances are also 
manufactured from it, such as starch, dextrine, glucose, 
sugar, oil, and solvents. From the cobs, pipes, xylose, 
sugar, and other articles can be made, while from the 
stalks, cane sugar, wall board, paper, artificial silk, and 
numerous other articles are manufactured. Let us begin 
with products obtained from the grain. 


In 1925 the United States produced 2,900,581,000 
bushels of corn, valued at $1,956,326,000. The firms 
producing com syrup, com sugar, com oil, and starch 
valued their products at $132,873,000. Of this amount 
$95,778,000 was the value of starch and the sugars and 
syrups obtained from starch by the acid action. 

The substances which make up the kernel vary widely 

in amount in accordance with breeding and cultivation; 

the following, however, is an average composition in parts 

per hundred: 

Per cent 

Water 19.6- 10.2 

Ash 1.2- 1.3 

Oil 3.0- 4.5 

Starch 60.0- 65.0 

Pentosans 7.0- 7.5 

Fiber 1.2- 1.5 

Protein 8.0- 10.0 

Total 100.0-100.0 

Starch and Oil. — Starch manufacture consists of the sep- 
aration of starch from the other substances of the kernel. 
At the end of the process of manufacture a bushel of com 


20 Field Museum op Natural History 


Starch 32,5 

Feed (20.8 lbs.) 

Gluten meal 6.9 

Corn bran 5.8 

Germ oil meal 2.0 

Steep water 5.3 

Corn oil 1.5 

Total 54.0 

In America the earliest processes for manufacturing 
starch embodied, first, the steeping in water of the grain 
at 77''-140° F., followed by grinding between rollers 
or buhr-stones, and the ground product washed in cylinder 
sieves. In sieving the hulls were separated from the starch. 
Next the starch and water mixture was run upon inclined 
troughs, and the starch granules deposited at the bottom 
of the troughs while the lighter gluten fiber ran off. The 
starch which had settled in the troughs was washed with 
a weak alkali solution to further remove gluten. Finally 
the starch was washed repeatedly with fresh water. 

The method in general use now is known as the sul- 
phurous acid method, first used in Europe. This was 
modified and improved and now consists of cleaning, 
steeping, grinding, sieving, tabling, washing, and drying. 

In cleaning the grain, fanning mills and sieves are 
used to separate chaff and light particles. Electromagnets 
draw out any iron which would injure the grinding 
machinery. The clean grain is taken to large, copper- 
bottomed steeping vats and steeped for thirty to forty 
hours with water containing 0.25 per cent to 0.30 per 
cent sulphurous acid (SO2). The sulphurous acid is used 
to prevent the formation of mildew or slime. By means of 
steam, the mixture is kept circulating and heated to a 
temperature between 115°-125° Fahrenheit. The heat- 
ing is done to soften the corn. The steep water contains 
the salts, soluble carbohydrates, and proteins, which pass 
out through the covering membranes of the corn kernel. 
This hquid contains about 20 per cent ash, 38 per cent 


Indian Corn 21 

protein, and 49 per cent carbohydrate and non-protein 
material. This water solution is concentrated by evapora- 
tion to a syrup and sprayed upon the com gluten feed 
before drying. 

The kernels softened by steeping are passed to Fuss 
mills. These mills are made up of two parallel vertical 
plates which rapidly revolve in opposite directions, and 
carry studs which project between each other. In these 
mills the kernel is broken, although the tough, rubbery 
germ at the tip of the grain passes out entire. The germ 
contains practically all of the oil in the grain and is 
extracted from the rest of the grain in germ separators. 
The germs are lighter in weight and are thus separated 
by the steaming process and ground in oil mills to express 
the oil. By far the most part of the oil is refined and 
sold as edible oil for use in salads and cooking. Unrefined 
com oil is used for soap-making and for nearly all pur- 
poses to which a semi-drying oil is adapted. The oil- 
press cake is used for cattle feed. After the removal of 
the germs the remainder, which consists of starch, gluten, 
and fiber, is mixed with water and ground again in buhr- 
stone mills. 

The thick, liquid mass is now passed over the shakers, 
which are tilted bolting cloth sieves of about 200 mesh, 
placed in a shaking apparatus. The starch and most of 
the gluten are washed through the bolting cloth. The 
fibrous portion tumbles off the lower end of the sieve. 

The liquid containing starch and gluten is passed 
from the shakers to inclined troughs, or tables. These 
wooden tables are about 100 feet long and 2 feet wide, 
with vertical sides. As the heavy liquid flows slowly 
down the tables the starch granules are deposited, while 
the gluten tends to pass down and off the tables. When 
the deposit of starch has become about ten inches thick, 


22 Field Museum of Natural History 

the flow of starchy Hquid is stopped, the gluten remain- 
ing on the surface of the starch is scraped off, and the 
deposited starch flushed off the table with water. 

The water containing gluten which comes from the 
starch tables is returned, after proper treatment, to the 
steeping vats. The starch after it comes from the settling 
tables is broken up and spread out upon trays made of 
wood and burlap. These trays are placed in carriers or 
wagons, and moved through kilns or drying tunnels in 
which a constant current of hot air is kept up. When 
a wagon and its contents are thoroughly dry, they are 
removed from the opposite end of the tunnel. 

Commercial Forms of Dried Starch. — In accordance 
with variations in the time and temperature of drying, 
different starches are formed. "Pearl starch" is dried 
about twenty hours at approximately 170° Fahrenheit. 
"Crystal starch" is formed when wet starch is placed 
in kilns in the form of a compact cube and drying con- 
tinued for a matter of weeks. Finally the mass contracts 
and breaks up into distorted prisms called crystals. 
The size of the crystals varies with the temperature, a 
low heat forming larger crystals. "Powdered starch" 
is made from "pearl starch" by pulverizing and sifting. 
"Lump starch" is made by treating powdered starch 
with steam and high pressure. The solid cylinder of 
starch which results is crushed and screened to size. 

Various Uses of Starch and Starch Modifications. — 
Starch when treated with acids or alkalis forms purified 
starches, soluble starches, thin-boiling starches, and 
alkaline thick-boiling starches. Dextrines are made by 
roasting slightly acidified starch under various degrees 
of temperature and pressure. Several forms of starch 
are used in the textile industries for stiffening and finish- 
ing warp and cop yarns; as a filler, finisher, and size in 
paper-making; for food uses in the manufacture of baking 


Indian Corn 23 

powders, pie fillings, pastes, sauces, jellies, and puddings; 
for laundry purposes; for dusting molds in foundries; 
and in the production of asbestos products, oilcloth, 
linoleum, explosives, paints, soaps, adhesives, coal 
briquettes, etc. Several varieties of dextrines are made 
use of in textile industries for sizing and stiffening the 
fiber, finishing the fabric, thickening the colors in calico 
and other printing, dressing leather, and in pastes, gums, 
glues, ink, fireworks, etc. 

Solvents. — Besides the above use for starch, there is 
another in which starch is transformed into solvents or 
lacquers used to a great extent in the automobile industry. 
Com although used to its greatest extent as a feed for 
animals and a food for man is not always fit for these 
purposes, as large quantities become spoiled. Previous 
to 1918, this low-grade com was used to a large extent 
in the making of whiskey and starch and its by-products. 
But now the solvent industry has become one of its 
largest users. 

Besides low-grade com unfit for consumption other 
carbohydrates may be used as raw materials for this 
process. The com is first screened to remove dirt and other 
fine matter, next passed through a magnetic separator 
to remove pieces of iron and steel, and finally ground in 
roller mills. The product from the roller mills is screened 
to separate the flour, and the larger particles are returned 
to the mill for further grinding. The membrane covering 
the kernels (bran) after separation from the flour is sold 
for feed. Generally whole corn is used in this process, but 
part of the corn may be degermed and only the starch 
used. All the com is not degermed because the germs 
contain protein, and too large a reduction in the amount 
of protein in the process would be objectionable, for 
protein is necessary to the growth of the micro-organisms 


24 Field Museum of Natural History 

used in the process. As much of the com is degermed 
as possible, however, as the oil obtained from the germs 
more than pays for the cost of separating it. 

A great amount of com meal is carried from the 
storage bins to the mashing vats. In the vats warm water 
is added and when the mixture has been made up to its 
proper consistency, the material is dropped into cookers. 
In the cookers, which are inclosed autoclaves, the material 
is cooked for two hours by live steam under pressure. This 
cooking is done to sterilize the material as well as to bring 
it to the proper condition for fermentation. At the end of 
the heating period the charge is blown by its own pressure 
from the cookers to the fermenters. On its way to the 
fermenters the sterile starch solution is cooled to below 
blood heat. At this point the mixture has about the 
consistency of ordinary flour paste. It is of interest to 
note that no malt is used and that the solution to be 
fermented contains starch and not sugar. Precautions 
are taken at the pipe lines, and storage vessels and fer- 
menters are protected from contamination by any wild 
yeast and fungi. 

The micro-organism used in the process to transform 
starch into solvents (butanol, acetone, and alcohol) is 
a bacterium, Clostridium acetobutyricum (Weizmann). A 
pure culture of this micro-organism is obtained, and 
before addition to the sterilized starch solution a large 
quantity of the micro-organism is obtained, so that it 
will outgrow any foreign micro-organism that might be 
present to contaminate the mixture. 

The Clostridium changes 3 pounds of starch into 1 
pound of mixed solvents in the form of a 2 3/^ per cent 
solution. During this change a gaseous mixture of 45 
per cent hydrogen and 55 per cent carbon dioxide is given 
off. The liquid solvent mixture obtained as a 23^ per cent 
solution consists of approximately 60 per cent butanol, 


Indian Corn 25 

30 per cent acetone, and 10 per cent ethanol. After 
fermentation the solution passes to a large reservoir 
from which it is pumped to stills. This is the only point 
in the process where mash is pumped. These stills are 
columns eight feet in diameter and fifty-four feet high. 
The 23^ per cent solvent mixture in passing through the 
stills is changed to a 50 per cent mixture. The resultant 
mixture is later fractionated in other stills into its three 
principal constituents, namely butanol, acetone, and eth- 
anol. This separation is made easier because of the fact 
that butanol and water form two layers. 

By-products are formed at three stages in the process. 
The first by-product is the bran or outer membrane of 
the kernel which is separated from the corn in the grind- 
ing process. The second by-product is the mixture of 
the hydrogen and carbon dioxide gases formed in the 
fermentation, and the third by-product is the waste from 
the stills. The bran, as already said, is sold for feed. 
The profitable disposition of the hydrogen and carbon di- 
oxide gases and the still waste are more complex problems. 
The hydrogen is readily separated from the carbon dioxide 
by the solution of the carbon dioxide in water. The 
hydrogen may find its commercial use in the manu- 
facture of ammonia. By passing the mixed hydrogen 
and carbon dioxide gases over heated carbon, a mixture 
of carbon monoxide and hydrogen is secured, which 
might serve for the manufacture of methanol. The 
waste from the stills contains about 1 per cent solid 
matter. These particles of solid matter may be removed 
readily by passing the waste through a fine screen. The 
particles collected in this way are nutritious and may be 
sold as feed. 


The com crop estimates of the United States govern- 
ment are based on bushels of shelled com. For each 
bushel of shelled com fourteen pounds of cobs have been 


26 Field Museum of Natural History 

harvested. For the four years 1923-27, an average of 
2,676,200,000 bushels of corn has been brought to 
market annually. Such an amount would be obtained 
from a yearly harvest of 19,000,000 tons of corncobs. Of 
this number approximately 1,444,800 tons of cobs were 
received at the grain elevators scattered throughout the 
corn belt. From these grain elevators the cobs could 
readily be obtained for manufacturing purposes. 

Tobacco Pipes. — Corncobs are perhaps best known in 
the form of tobacco pipes called Kentucky or Missouri 
"meerschaums." However, they use but a very small 
fraction of the annual product of corncobs. 

Fuel. — At the present time corncobs have their 
greatest use as fuel. In the western states the fuel supply 
used to be uncertain and many cobs, as well as full ears 
of corn, were used as fuel. In fuel value three tons of corn- 
cobs equal one ton of hard coal. In France, the cobs, 
soaked in resinous matter (sixty parts melted resin and 
forty parts tar) were formerly used as fire lighters and 
were bought at from twelve to twenty francs. 

Potash. — Corncobs contain a large amount of potash, 
in fact more potash than any other mineral constituent. 
Mills which shell corn frequently use cobs as fuel. A 
mill shelling 5,000 bushels an hour has 7,000 pounds of 
cobs per hour. The ashes in the mill are collected for 
the extraction of potash. One thousand cobs yield 7.62 
pounds of potassium carbonate, or in a factory of the 
above capacity, 535 pounds per ten-hour day. Experi- 
ments have been carried on with the use of impure 
corncob ashes as a water softener. 

Meat-smoking. — Meat-smoking and bee-smoking have 
been carried on successfully by the use of corncobs. 

Insulating Material. — During the last few years a 
product has appeared in the Chicago markets made out 
of corncobs to be used for insulating houses already con- 

[ 240 ] 

Indian Corn 27 

structed. It is called kalkite, with the accredited com- 
position of nineteen parts corncobs, twelve parts gypsum, 
and two parts waste paper and chemicals. Corncobs, 
bought at grain elevators for a dollar a ton loaded on the 
cars, are ground up to the fineness of granulated cork. The 
gypsum acts as a binder, and together with the other 
chemicals makes a product vermin-proof and practically 
fireproof. Houses are insulated with this material 
without disturbing the contents. Holes are bored in the 
plate between the studs in the attic, and the wall space is 
filled with a mixture of kalkite and 10 per cent water. 
The space between the floors is filled with the material 
in similar manner. On a floor the product weighs about 
4^ pounds per square foot. Kalkite has been tested by 
the United States Bureau of Standards and shows a heat 
conductivity of forty British thermal units per hour, per 
square foot, per one inch in thickness, per one degree 
Fahrenheit change in temperature. 

Miscellaneous Uses. — Corncob flour has been substi- 
tuted for wood flour in many ways, for example as a 
basis for punk and incense and in curing concrete 
floors in place of sawdust. Corncob flour has also been 
substituted for bran in removing oil from tin plate in the 
tin-plating industry. Corncobs heated with water and 
steam under pressure produce a powerful adhesive. 
When corncobs are subjected to destructive distillation, 
products similar to those obtained from wood are secured, 
that is, charcoal, acetic acid, wood alcohol, tar, illumi- 
nating gas, and alcohol. The charcoal has been found to 
be an excellent medicinal charcoal. Under suitable 
treatment it forms a very good decolorizer. 

Xylose or Wood Sugar. — This sugar may be obtained 
from corncobs by boiling them with dilute sulphuric 
acid. It is found occurring naturally in the nucleo- 
proteids of plants and animals, and is perhaps the only 


28 Field Museum of Natural History 

sugar made up of five carbon atoms to be found in 
animals. It is about one-half as sweet as cane sugar^ 
whereas glucose from starch is three-fourths as sweet as 
cane sugar. Xylose does not ferment with yeast and 
therefore is probably indigestible and without food value 
to man. It may, however, be of use as a sweetener for 
the food of persons suffering from diabetes. Xylose may 
be obtained not only from corncobs but also by the 
action of dilute sulphuric acid on bran, straw, and various 
other vegetable products. 

Fwr/wra/.— Furfuraldehyde or furfural is formed when 
xylose is distilled with hydrochloric (muriatic) acid or 
with dilute sulphuric acid (vitriol). It is more practical 
to obtain furfural by distilling a mixture of dilute hydro- 
chloric acid and ground corncobs. The distilling vapor 
is condensed to a mixture of furfural and water which 
may be fractionated to produce almost pure furfural. 
Furfural, like formaldehyde, will form a hard resin 
similar to bakelite. The resin formed can be used in 
varnishes or when added to a suitable filler such as wood 
or corncob flour as a molding resin. Resin may be formed 
from furfural by the addition of phenol (carbolic acid), 
or may be made directly in the ground cobs by the 
addition of hydrochloric acid and phenol. 

Furfural acts as a preservative, and has been used in 
veterinary embalming fluid and for other purposes. It 
is also a solvent for nitro-cellulose and cellulose acetate. 
As a solvent it removes varnish readily. During the war 
it was used in "dope" for airplane wings. The Chemical 
Department of the Iowa State College has made a num- 
ber of dyes and anaesthetics from furfural. It has been 
used as an accelerator in rubber curing. It can also be 
used as a fuel to replace gasoline, although its expense 
makes it impractical for present use for that purpose. 
When added to gasoline it forms an anti-knock motor 

[ 242 ] 

Indian Corn 29 

The yield of furfural from corncobs is about 10 per 
cent of their weight. An equivalent amount can also be 
produced from oat hulls and other material. This is 
about half the laboratory or theoretical yield. Cotton- 
seed bran yields 22 per cent, which is double the amount 
from corncobs. Because oat hulls and cottonseed hulls 
are produced over a large period each year, they are 
more desirable as a source of furfural than corncobs, 
which are only at present available in the elevators from 
November to May. 


Syrup. — Most of the different plants of the grass 
family have hollow stems, but there are three notable 
exceptions: sorghum, sugar cane, and corn. All three 
contain cane sugar. The Aztecs in Mexico made use of 
the corn plant for sugar, in the same manner as sugar 
cane is now used. An interesting review of the trade in 
com sugar in Colonial days is given by Collier in his book 
on sorghum sugar. Work carried on at the Minnesota 
Agricultural Experiment Station resulted in the following: 
a cannery which cans only com has available approxi- 
mately 500 acres of stalks or 4,000 tons per year, which 
could produce 1,100 gallons of syrup per day, or 38,000 
during a season. In the Minnesota experiments five 
varieties of sweet com and two of field com were used. 
When the com is ripe enough to can, the juice of the 
stalks contains 9-11 per cent cane sugar. If the stalks 
stand in the field twenty days after the removal of the 
ears, the amount of sugar in the stalk increases to 13-17 
per cent. The proper stage for syrup-making is during 
the time of maximum amount of sugar in the juice, not 
only because of the yield but because of the quality of 
the juice. Cornstalk syrup may be manufactured by 
nearly the same process as sorghum syrup. The con- 
trolled defecation, filtration, and vacuum evaporation 
may be used. Cornstalk syrup is clear, reddish amber in 


30 Field Museum of Natural History 

color, with a pleasant flavor. As produced, it is not a 
table syrup but an excellent cooking syrup considered 
equal to the best grades of sorghum and cane molasses. 
As estimated by the Minnesota Experiment Station, the 
commercial manufacture of cornstalk syrup is not very 
profitable. They assume that three dollars per ton of 
fresh stalks would be satisfactory to the grower. This 
would amount to eighteen or twenty-one cents per gallon 
of syrup. Actual cost of manufacture is considered as 
thirty cents. The total cost is consequently about fifty 
cents per gallon, and could sell wholesale at about sixty- 
eight cents to compete successfully with the best grade 
of sorghum syrup. If the manufacturing plant cost 
$60,000 the returns at sixty-eight cents per gallon for 
syrup would be about 11 per cent. These figures allow 
for the utilization of bagasse and leaves. 

Wall Board. — The usual height of cornstalks in the 
Com Belt is from six to ten feet, although the plant has 
been known to grow anywhere from eighteen inches to 
twenty-four feet high. The stalk consists of a hard outer 
shell inclosing a center of soft pith. This outer shell is 
made up of many bundles of long, thin fibers and micro- 
scopic tubes called fibrovascular bundles. Some fibro- 
vascular bundles also appear in the pith. The leaves on 
the cornstalk are attached every eight or ten inches along 
the stem. At these points of attachment the fibrovascular 
bundles going to the leaves from the stem form hard, 
dense portions, known as nodes. The soft pith is com- 
posed of flat, non-fibrous cells. 

As tall office buildings have frameworks of steel, so 
cornstalks have frameworks of cellulose fibers. Conse- 
quently cellulose makes up 45 per cent of their total 
weight. It is interesting to note that various woods 
contain 48-62 per cent of cellulose. Another constituent 
of cornstalks is lignin, to the extent of 31 per cent, which 

[ 244 ] 

Indian Corn 31 

equals the average content of lignin in woods. Char- 
acteristic constituents of cornstalks are their pentosans, 
which make up over 27 per cent of their weight, while in 
common woods the percentage varies between 7 and 25. 
The chemical difference between the hard portion of the 
stalk and the soft pith apparently is slight, while their 
physical characters differ very greatly. Com leaves are 
lower in cellulose than the stalks or husks. The cobs also 
have a lower cellulose content, but are higher in pentosans. 
A chemical analj^sis of cornstalks and cobs shows them 
to be not greatly different from wood. 

Wall board can be made from cornstalks by the use 
of machinery, water, heat, and pressure. By the use of a 
paper beater or rod mill the long, strong fibrovascular 
bundles are torn apart by shredding and beating in water. 
The beating is continued until the fibers are of the proper 
length. In so doing they have absorbed a large quantity 
of water and become slightly sticky on the surface. When 
pressed together and dried, they form board. Cooking 
under pressure increases the property of sticking together. 
The use of such board as building material has rapidly 
developed. A short time ago wall board and insulating 
board were used only in temporary partitions or in cheap 
repair work, and were considered suitable only for such 
uses. Today, however, a great deal is used in the making 
of houses of the better sort. The heat and sound insulating 
properties of such materials are due to the minute air 
pockets between the fibers, which efficiently interfere with 
the circulation of air and heat and the transmission of 
sound. Other, similar boards are made from wood, 
wheat straw, flax straw, sugar cane waste, licorice root 
waste, cork, etc. These boards when used in buildings 
form a substitute for lath and plaster or serve as a plaster 
base or as sheathing either beneath wooden siding or 
under stone or brick veneer. 


32 Field Museum of Natural History 

A hard, dense form of board has been made with the 
joint appHcation of heat and pressure in a special type 
of hydraulic press. Such boards resemble a very hard, 
grainless wood, suitable for use as panels. Another form 
of useful material is made by impregnating the felted 
material with synthetic resin. 

Paper. — Besides wall board, cornstalks can be made 
into paper. Experiments have been conducted by the 
United States government in cooperation with Iowa 
State College, where the entire cornstalks have been 
made into paper without any attempt at separation of 
the parts. Good paper can be made by various processes. 
Excellent paper of the quality used in books and writing 
paper may be produced by the "soda process." This 
method involves cooking the stalks in caustic soda or 
lye. Paper made by a somewhat modified "soda process," 
called the Dorner process, now appears for sale. The 
Kraft method furnishes a good brown wrapping paper. 
A cheap mechanical pulp paper suitable for newspapers 
is being developed. 

Artificial Silk. — Further refinement of paper pulp 
results in a substance known as alpha cellulose. Alpha 
cellulose is the basic material for rayon, or artificial silk. 
The commercial output of rayon at present comes from 
wood and cotton. Experimental work in a rayon factory 
showed that high-grade rayon can be made from corn- 
stalk pulp by any of the three methods now in common 

Statistics on Cornstalk Production. — The United States 
produced annually an average of 2,676,220,000 bushels 
of corn for the four years 1923 to 1927, inclusive. Assum- 
ing that 84 per cent of the crop was harvested for grain, 
and that the stover-grain ratio was 150, the amount of 
stover produced annually would be 94,000,000 tons. If 
one-third of the weight of stover consisted of water at 
the time it was harvested, there would be not less than 


Indian Corn 33 

62,000,000 tons of bone-dry material for use in wall 
board, paper, or artificial silk manufacture. One ton of 
cornstalks is said to make 2,000 square feet of wall board. 
The yearly production of cornstalks in Iowa available 
for manufacture is estimated as 10,000,000 moisture-free 
tons. Iowa could therefore make each year from unused 
cornstalks 20,000,000,000 square feet of wall board. 

The average yield of stalks per acre is calculated at 
a minimum of one and one-half tons. In Iowa one-third 
of the land is considered as planted in com. Therefore a 
manufacturing plant in operation 300 days a year could 
obtain eighty tons of stalks a day from within a five-mile 
radius or 335 tons a day within a ten-mile radius. In 
that part of Iowa where 60 per cent of the land is planted 
in com, a radius of five miles will give 150 tons of stalks 
a day and ten miles will yield 600 tons of stalks a day. 
According to these estimates, the length of haul to supply 
even a fairly large factory would be short. 

To determine the proper method of harvesting corn- 
stalks, the Agricultural Engineering Department of Iowa 
State College carried on an extensive study. As a result, 
a machine has been made which both cuts and bales the 
stalks as it goes over the field. The machine is a com- 
bination of a mower, a hay loader, and a baler, made into 
one, and pulled by a tractor. Two men are needed to oper- 
ate the machine. Cost of operation is considered to be 
$2.40 per ton. 

On the farm the immatiu^e, green stalks together with 
the grain are used in making silage, a very good food for 
farm animals. The mature, fully grown stalks from which 
the ripe ears of com have been gathered have very little 
food value, but do have a commercial value in the manu- 
facture of wall board and paper. At the present time they 
are for the most part ploughed under for fertilizer or 
burned to clear the field for the spring ploughing. 

James B. McNair 




An exhibit of corn and products derived from corn kernels such 
as oil, starch, glucose, and alcohol is to be found in Hall 25 in Field 
Museum. In Hall 28 will be found the various industrial products 
derived from cornstalks, cobs, kernels, and husks such as wall board, 
paper, and solvents.