Factors Influencing the Absorption of Sodium Fluoride by the American Cockroach

Abstract

The time required for the cockroach (Periplaneta americana) to absorb a lethal dose of NaF through the body integument was studied. The injection of various salt solns. into the body fluid of the roach altered the time of absorption in such a way as to indicate that the body wall acts as a semiperme-able membrane. The effect of mixing with the NaF certain other powdered chemicals such as lime is interpreted to indicate the presence of a layer of oily secretion on the body integument that acts as a protective coat tending to reduce the speed of absorption of the NaF.