Studies on the toxicity of nicotine in combination with various adjuvants.

Any material used in combination with nicotine to produce a more effective kill than would be otherwise obtained by using nicotine alone, may be termed an adjuvant of the nicotine. The adjuvant may or may not have toxic qualities in itself, depending on such factors as the species of insect concerned and the meteorological conditions at the time of application. The effect which an adjuvant has upon nicotine may be due to either physical or chemical factors but more probably to a combination of both. Physically, the adjuvant may bring about more effective spreading and sticking, with greater ability to withstand cranging climatic conditions. The adjuvant may also produce a smothering effect. Chemically, as an "activator" , it may hasten the evolution of free nicotine by the reaction of the basic and acidic radicals of the soap and nicotine sulphate. An adjuvant may also act chemically by producing an affinity between itself and the surface of the solid, through chemical combination with contaminants on the surface or by dissolving protective coatings, such as wax. [...