why do insects die? T o create insecticides, chemists must know how insects react to certain chemicals. One of the most interesting stories can be told about ο,ο-diethyl o-pnitrophenyl thiophosphate, commonly called parathion. Body nerves contain a chemical called acetylcho line, which helps to transmit nerve impulses. After the impulse is transmitted, an enzyme destroys this chemical. Parathion (which the body converts to paraoxone) destroys the enzyme, and this allows the acetylcholine to accumulate in the system. The in sect's body goes into uncontrollable nervous activity, causing tremors, convulsions, paralysis and death. Parathion is prepared by treating thiophosphoryl chloride with sodium ethylate and allowing the prod uct of this reaction to condense with sodium pnitrophenate, a derivative of U S S One-Degree Nitration-Grade Benzene. United States Steel, 525 William Perm Place, Pittsburgh 30, Pennsylvania. USS is a registered
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(UsS) Chemicals Sa/es Offices in Pittsburgh,
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