In previous communications,1 results of experimental studies were reported from which it appears that in the rabbit there is an inverse relation between the degree of cutaneous irritability and the calcium content of the skin and a direct relation between the degree of cutaneous irritability and the potassium content of the skin. In another communication, experimental data were reviewed which show that the potassium-calcium ratio acts as a regulator of the autonomic nervous system. Results of experimentation were reported in which the obverse of this principle when applied to the skin was studied. The vegetative nervous system in rabbits was pharmacologically disturbed. As a result of such study, it was concluded that cutaneous irritability in the rabbit was altered following the administration of drugs that act on the autonomic nervous system. It appeared from data submitted that the potassium-calcium ratio in the skin of most of the rabbits studied