The Terms “Chronaxie” and “Rheobase” are 100 Years Old

“The excitability of a biological object cannot be considered as defined, if only one excitation threshold is determined. Such an isolated determination is not suited for the simplest and direct comparison whether, for instance, the excitability is augmented or diminished under influencing conditions. If it is stated that a simply applied stimulus has to be augmented or diminished, is this statement only valuable for this particular stimulation and cannot be applied to the general excitability of the object; and, indeed, another stimulus, different from the first in duration, may give a completely different result, even a variation in an inverse sense.”