The Stimulative Effect of Roentgen Rays Upon the Glands of Internal Secretion*

Arndt in explanation of experiments with medicinal drugs, expounded the following as a biological concept: “Weak stimuli accelerate vital processes, moderate promote them, strong inhibit them and strongest destroy them” “[Kleine (schwache) Reize fachen die Lebenstatikeit an, mittle starke forden sie, starke hemmen sie, und starkste heben sie auf].” This hypothesis was elaborated by Schultz in 1899 into what now is known as the Arndt-Schultz Law. It has since been extended to serve as the basis for stimulative radiation and also as the main point of difference between the various investigators in this field. The very wording of the hypothesis has given rise to contentions as to its proper meaning, the term stimulus especially being the cause of controversial discussion. Holzknecht and Pordes consider that the word itself is ambiguous and vague and that it is used in a different sense from that embraced in the expression “stimulative effect.” According to Dejardins, stimulation in the physiological sense occurs whenever any reaction takes place between two bodies and is capable of producing a positive or negative response.