arsenic, which is still the basic ingredient in a variety of weed and insect killers. Arsenic is a
highly toxic mineral occurring widely in association with the ores of various metals, and in very
small amounts in volcanoes, in the sea, and in spring water. Its relations to man are varied and
historic. Since many of its compounds are tasteless, it has been a favorite agent of homicide
from long before the ti me of the Borgias to the pres ent. Ars enic is pres ent in Englis h chimney
soot and along with certain aromatic hydrocarbons is cons idered res pons ible for the
carcinogenic (or cancer-causing) action of the s oot, which was recognized nearly two centuries
ago by an Englis h phys ician. Epidemics of chronic ars enical pois oning involving whole
populations over long periods are on record. Ars enic-conta minated environments have als o
caus ed s icknes s and death among hors es , cows , g oa ts, pigs , deer, fis hes , and bees ; des pite this
record ars enical s prays and dus ts are widely us ed. In the ars enic-s prayed cotton country of
s outhern United States beekeeping as an indus try has nearly died out. Farmers us ing ars enic
dus ts over long periods have been afflicted with chronic ars enic pois oning, lives tock have been
pois oned by crop s prays or weed killers containing arsenic. Drifting arsenic dusts from
blueberry lands have s pread over neighbori ng farms , conta minating streams, fatally poisoning
bees and cows, and causing human illness. ‘It is scarcely possible...to handle arsenicals with
more utter dis regard of the gene ral health than that which has been practiced in our country in
recent years ,’ s aid Dr. W. C. Hueper, of the Nati onal Cancer Ins titute, an authority on
environme ntal cancer. ‘Anyone who has watched the dus ters and s prayers of ars enical
ins ecticides at work mus t have been impres s ed by the almos t s upreme careles s ness with which
the pois onous s ubs tances are dis pens ed.’...
Modern ins ecticides are still more deadly. The vast majority fall into one of two large groups of
chemicals. One, repres ented by DDT, is known as the ‘chlorinated hydrocarbons. The other
group c ons is ts of the organic phos phorus ins ecticides , and is repres ented by the reasonably
familiar malathion and parathion. All have one thing in common. As mentioned a bove, they are
built on a bas is of carbon atoms , which are als o the indis pens able building blocks of the living
worl d, and thus class ed as ‘organic’. To unders tand the m, we mus t s ee of what they are made,
and how, although linked with the basic chemistry of all life, they lend themselves to the
modifications which make them agents of death.
The basic element, carbon, is one whose atoms have an almost infinite capacity for uniting with
each other in chains and rings and various other configurations , and for becoming linked with
atoms of othe r s ubs tances. Indeed, the incredible diversity of living creatures from bacteria to
the great blue whale is largely due to this capacity of carbon. The complex protein molecule has
the carbon atom as its basis, as have molecules of fat, carbohydrates, enzymes, and vitamins.
So, too, have enormous numbers of nonliving things , for carbon is not necess arily a s ymbol of
life. Some o rg a ni c comp ounds are s imply combinations of carbon and hy drogen. The s imples t
of these is methane, or mars h gas , formed in nature by the bacte rial decompos ition of organic
matte r unde r water. Mixed with air in proper proportions , methane becomes the dreaded ‘fire
da mp’ of coal mines. Its structure is beautifully simple, consisting of one carbon atom to which
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