A nerve pressed upon by a fractured or a luxated bone would be stretched were it not for the responsive principle of life which resists pressure. The impulsive force normally conveyed by the nerve is modified by the elastic resistance known as renitency. The result is either too much or not enough function, conditions known as disease. The contraction and expansion of the nervous system has a normal limit known as tone, the basis upon which I founded the science of chiropractic. Any deviation therefrom is recognized as disease.
Tone denotes normal temperature, normal structure, normal tension and normal vibration of nerves.
An angleworm, when relaxed, may measure six inches. This ability of elastic resistance to any opposing force is an inherent quality of all living matter. Dead material does not possess it. An impingement upon a nerve calls into action two opposing forces. The impinging body tends to stretch the nerves, while the inherent principle of self-preservation exerts an activity toward contracting it.