The most important symptom of fully developed lead poisoning is colic, which is usually preceded by the initial symptoms described (especially the gastric symptoms), but not always so, as occasionally colic sets in without any warning. The colic pains often set in with marked vehemence. They radiate from the navel on all sides, even through the whole body; the abdomen is contracted and as hard as a board. Pressure on the lower part diminishes the pain somewhat, so that the sufferer often involuntarily lies flat on his stomach. During the attack the pulse is often remarkably slow. Constipation occurs, and often does not yield to purgatives. The attacks last sometimes for hours, occasionally for days, or the pains can (with remissions) even distress the patient for weeks. The frequency of attacks is also very variable. Occasionally one attack follows another, often there are intervals of weeks, even years, according to the severity of the poisoning and duration of exposure. If the patient is removed from the injurious action of lead, as a rule recovery soon ensues. [Illustration: FIG. 34.—Paralysis of the Ulnar Nerve in Lead Poisoning] [Illustration: FIG. 34A.—Different Types of Paralysis of the Radial Nerve in Hungarian Potters poisoned by Lead (_after Chyzer_)] Often with the colic, or at any rate shortly after it, appear lead tremor and arthralgia, paroxysmal pain mostly affecting the joints, but occasionally also the muscles and bones. They are often the precursor of severe nervous symptoms which affect the peripheral and central nervous system. In a lead poisoning case running a typical course the predominant feature is the peripheral motor paralysis of the extensors of the forearms. Next the muscles supplied by the radial and ulnar nerves are affected. Often the progress of the paralysis is typical; it begins with paralysis of the extensor digitorum communis, passes on to the remaining extensors, then to the abductor muscles of the hand; the supinator longus and triceps escape. Sometimes the shoulder muscles are attacked; also paralysis in the region supplied by the facial nerve and of the lower extremities is observed. It appears plausible that overstrain of single groups of muscles plays a decisive part; this seems proved by the fact that paralysis first affects, among right-handed people, the right hand (especially of painters), but in the case of left-handed, the left hand; and among children the lower extremities are often attacked first. Disturbance of sight increasing to amaurosis is often an indication of severe brain symptoms. The view of some writers that the cause of the sight disturbance lies in vasomotor influences (cramp of the bloodvessels) is very probable, and supports the view that the brain symptoms are entirely due to diseases of the arteries (arteritis). These symptoms are distinguished by the collective name of saturnine encephalopathy; they include apoplexy, hemiplegia, epilepsy, delirium, and mania.