After a dose of from 1 to 2 oz. the symptoms begin quickly with the characteristic taste of the drug, followed, perhaps, in a quarter of an hour by burning and pricking in the gullet, nausea and vomiting, but the vomiting caused by the poison alone is not usually severe; there is uneasiness in the stomach sometimes followed by violent colic, but the pain intermits, and it may be relieved by pressure. There is usually constipation, but sometimes an attack of purging, the faeces being dark, and containing lead sulphide.

Subacute poisoning may be illustrated by cases which occurred at Stourbridge in 1849, when acetate of lead was mixed by accident with flour at a miller's. Upward of five hundred persons were attacked, a few days after eating the bread, with a sense of constriction about the throat and stomach, cramping pain near the umbilicus, and rigidity of abdominal muscles; sickness occurred only in a minority of the cases, and did not last long; there was obstinate constipation and a general lessening of secretion; a dark blue line on the gums was noted. No cases were fatal, but severe symptoms continued for a long time, and sometimes recurred after apparent convalescence.

The subject of chronic lead-poisoning is exceedingly interesting to the practical physician, but concerns us at present only as illustrating the physiological action of the drug. Some of its symptoms have occurred from the medicinal use of the acetate, and from the continued use of minute quantities rather than from massive doses. Thus, Sir R. Christi-son gave 18 gr. in two days without injurious effects, while 1/15 gr. given two or three times daily for two months caused fatal poisoning in a child (Letheby, Taylor). As a rule, it may be said that the worst effects of any medicinal use of lead limit themselves to an attack of colic, and the severe symptoms about to be described need not be feared from it: 5-gr. doses of acetate are largely used at Brompton Hospital without bad results.

The ordinary "lead colic," or plumbism, is traceable most frequently either to the mechanical use of metallic lead, its oxides or carbonates, or to the solution of these salts in drinking-water, etc. (v. p. 257). After some general malaise, disordered taste, dryness of mouth, fetid breath, anorexia, and constipation, pain will usually be the most marked symptom, but is not so invariably; Dr. Garrod finds it absent in 2 or 3 per cent. of cases. When fully developed, it is much more intense than ordinary colic; it is referred mainly to the region of the navel (the colon), but darts rapidly, like neuralgic pain, in many directions, toward the loins, the scrotum, the chest, and the thighs: it has a twisting, tearing character, so that German miners name it commonly "Hutten Katze" ("cat of mines"). It comes on in paroxysms, remaining constant but dull in the intervals, and the whole attack lasting from a few minutes to several hours; it is often worse at night, but its recurrence is irregular. Relief is found from firm pressure and altered position, and the sufferer either lies flat on his face, pressing the abdomen, or is doubled up, bending his legs, or rises suddenly, still pressing the painful part with his hands, till a violent paroxysm again sends him to bed. Restlessness is extreme, and the whole attention is concentrated on the pain. The abdominal walls are rigid, knotty, and drawn in, there is commonly tenesmus, and the rectum has been felt to contract and relax spasmodically. The liver is retracted (Potain) or actually lessened in size; the intestines also are drawn into less space from contraction of their muscular coat, and in prolonged cases, after the abdominal fat has been absorbed, the retraction of the belly becomes very striking.

Tanquerel (Traite des Maladies de Plomb, Paris, 1839) and Burton ("Medico-Chirurgical Transactions," 1840) were the first to describe as common in plumbism a dark blue or gray line along the free edge of the gum, together with a brownish coloration of the teeth. Though a valuable sign, and often present, it is not always so, nor does it necessarily imply saturation of the system with the mineral; it varies in its time of appearance according to the dose, but has been seen within twenty-four hours of administration of one large quantity (Burton): 20 to 30 gr., in divided doses, may develop it, and when once seen it is very persistent; similar colored patches may often be found on the buccal mucous membrane. The coloring depends on formation and deposition of lead sulphide from the sulphuretted hydrogen evolved from particles of food left about the teeth (Tomes), and by perfect cleanliness it may be prevented. According to Dr. Hilton Fagge, it is distributed in rounded loops corresponding with vascular papillae of mucous membrane, and depends on small pigmented granules, some of which are external to, others within the small vessels. He concludes that the gas from food-particles diffuses into the gum-textures, and then combines with lead circulating in blood or plasma, so that particles of lead sulphide are really precipitated - a similar condition may be present in the intestinal membrane. Iodide of potassium sometimes induces its rapid development (Lancet, i., 1876, p. 709).

We cannot so readily explain the pathology of the colic. It is in part dependent on constipation, or accumulated mucus within the canal, for it is relieved when purgation is secured; yet Briquet claims to have relieved more quickly by faradaism of the abdominal wall without any aperient effect. It is dependent partly also on irregular muscular contraction of the intestinal tube, following on partial paralysis and spasmodic peristalsis; other characters again show it connected with an enteric neuralgia (v. p. 254).

In acute poisoning, the gastro-intestinal mucous membrane has been found coated with a whitish-gray layer of coagulated mucus containing the poison, and there have been patches of abrasion, congestion, or inflammation. In chronic cases the membrane is congested, softened, and discolored, the walls are thickened, and the canal irregularly contracted; sometimes intussusceptions are found; the coils of intestine are closely packed together. In chronic plumbism, emaciation is notable, especially about the face.