By F.R. CAMPBELL, A.B., M.D.
The cereals are subject to many diseases which retard their development,
rendering them unfit for food, and even poisonous. The relation of
unwholesome foods to the diseases of the animal body are now being
thoroughly studied, recent advances in chemistry and microscopy
contributing valuable aid to the prosecution of such investigations.
Some enthusiastic advocates of the germ theory of disease believe that
many, if not all, the so-called disease germs may be transplanted into
the human system with the food ingested. But whatever may be the real
truth in regard to this subject, it has been positively demonstrated
that many diseases of the human body may be produced by unwholesome
food. The specific symptoms produced in man by the various grain
diseases are not accurately known, consequently our remarks upon this
subject must be of a very general character.
Pappenheim divides the diseases of the cereals into two classes,
internal and external. The internal diseases are those depending upon
conditions of soil, climate, cultivation, etc., and may be neglected in
our discussion, as they produce no special disease of the body, only
impairing the nutritive value of the grain.
The external diseases are of much greater importance, as they probably
produce some of the most fatal maladies to which the human race is
subject. These external diseases of the cereals are due to parasites,
which may be either of an animal or vegetable nature. Among the animal
parasites may be mentioned the _weevil, vibrio tritici_, which feeds
upon the starch cells of the grain. Grain attacked by this parasite was
at one time supposed to be injurious to health.
In 1844 the French Commission appointed to examine grain condemned a
large quantity imported with this parasite, but afterward reconsidered
their decision and permitted its sale, concluding that it was deficient
in nutritive properties, but not otherwise unwholesome. Rust is the most
common disease of the cereals, produced by vegetable parasites. Like
the other diseases of this class, it is most prevalent in warm, damp
seasons.
Prof. Hensboro is of the opinion that rust is but an earlier stage of
mildew or blight, the one form of parasite being capable of development
into the other, and the fructification characteristic of the two
supposed genera having been evolved on one and the same individual.
Blight is a term loosely applied to a number of parasitic diseases.
In it are included mildew, cories, and even rust and smut. The fungi
producing these diseases attack the plant and seed at various stages of
its growth. The whole kernel is affected, and not merely the external
coat, as is sometimes maintained. When blighted grain is sown, the
disease recurs the following year, often making it necessary to import
new seed before the disease can be eradicated. Various remedies have
been used to destroy the spores of these fungi, but all are uncertain
and some are dangerous to health. Special machinery and methods have
been employed in the mills to separate the mildew from the grain. Some
of these succeed in removing the fungi and discoloration from the
surface of the grain, but have no effects upon the parts within.
Blighted grain is soft, and has an unpleasant taste and smell, and bread
made of it is liable to be heavy and sodden.
It is undeniable that the use of blighted grain as food is exceeding
dangerous to health. It is a well known fact that vegetable parasites
may attack animals; the silk worm disease produced by the _Botrytis
baniana_, being an example. It is stated that the same vegetable
parasites which produce plant diseases, when transmitted to the animal
body produce special affections, the form and appearance of the germs
being altered by their environments. The same germs developed under
different conditions of temperature and surrounding medium, assume forms
so various that they have been supposed to belong to different species
and even different genera. If there is any truth, then, in the germ
theory of disease, it is not so very improbable that a fungus which
will produce blight in grain may cause cholera or tetanoid fever in an
animal.
Hallier, the famous physiological botanist, observed in 1867 that there
was a peculiar disease of the rice plant associated with an epidemic of
cholera. Rice plants fertilized with the discharges of cholera patients
were affected with blight. A concentrated infusion of the blighted grain
would produce changes in all animal substances, blood and albumen being
converted into thin odorless products resembling in every respect the
material found in the kidneys of cholera patients.
The most formidable of the diseases attributed to the use of diseased
grain is cerebro-spinal meningitis, commonly known as spotted or blanoid
fever. The disease is rare in England, but is frequently epidemic in the
United States, in Ireland, and on the Continent. In 1873, in the State
of Massachusetts alone, 747 persons died of it, and other epidemics even
more fatal have lately occurred in New York and Michigan. The disease is
a nervous fever attended with convulsions, the pathological lesion being
congestion and inflammation of the membrane of the spinal cord and
brain. Dr. Richardson in writing on the nature and causes of spotted
fever concludes that it is due to the use of diseased vegetable
substances, especially grain, and from a careful analysis of the
statistics of this disease reported by the Michigan State Board of
Health considers it demonstrated that "under favoring condition for its
action diseased grain received as a food is the primary cause of the
phenomena which characterize the disease." These views are substantiated
by the experiments of Dr. H. Day, who found that by feeding rabbits on
unsound grain, spasmodic affections were produced, due to inflammation
of the membranes of the spinal cord and brain.
In warm climates, pellagra or Italian leprosy is said to be produced by
eating diseased maize, which forms the principal article of food among
the poorer classes of the rural districts. Pellagra is epidemic in
northern Italy and the south of France. The disease is manifested by a
redness and discoloration of the exposed parts of the body. It is most
active during the hot weather, the inflammation subsiding in the winter,
leaving a pigmentation of the skin. Each year the symptoms become more
alarming, nervous disorders finally setting in, and a large number die
insane. The disease is most prevalent in the country. In the towns,
where maize is supplemented by other articles of food, it does not
exist.
Ergot is a very common disease of the cereals. The fungus producing it
was discovered in 1853, but for centuries previous its injurious effects
upon the human body were recognized, and it was observed that ergot of
rye was the most poisonous. Taken in large doses, ergot will produce
nausea, vomiting, diarrhoea, headache, and weakness of the heart. In
small repeated doses it will produce contraction of all the unstriped
muscles, as those of the blood vessels, the womb, and intestines.
Ergotium is the name given to the disease produced by the continued use
of grain affected by this fungus. Aitken describes it as "a train of
morbid symptoms produced by the slow and cumulative action of a specific
poison peculiar to wheat and rye, which produces convulsions, gangrene
of the extremities, and death. In countries where rye bread is much used
ergotium is sometimes epidemic. This was a frequent calamity before
the introduction of suitable purifiers into the mills. There are two
varieties of the disease, the convulsive and the gangrenous. The
convulsive form begins with tingling of the extremities, drowsiness, and
headache, followed by pain in the joints, violent muscular contractions,
and death. The gangrenous variety begins with coldness and weakness
of the extremities followed by gangrene and sloughing. This form is
somewhat more fatal than the convulsive, the mortality of those affected
being about 90 per cent.
Mouldy grain and bread have also caused poisoning. Prof. Varnell states
that "six horses died in three days from eating mouldy oats. There was a
large amount of matted mycelium, and this when given to other horses for
experiment, killed them within thirty-six hours." The writer has himself
seen seven hogs die within a few days while being fed on mouldy corn.
Flour which has become stale may produce similar injurious effects,
although most of the germs are destroyed in the process of baking. It is
quite probable, however, that a poisonous substance is generated by the
mould fungus, which cannot be destroyed in this way.--_Milling World_.
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