N.B.—The symptoms produced by white lead—carbonate of lead—are those of colica pictonum, or painter‘s colic, described under the head of Chronic Lead Poisoning.
Post-mortem Appearances.—In acute poisoning the mucous membrane of the stomach and intestines is inflamed, and is in some cases covered by layers of white or whitish-yellow mucus, more or less impregnated with the salt of lead swallowed. Corrosion of the mucous membrane may occur if the dose be large, and this condition is more frequently present when the neutral salt is taken.
In chronic poisoning there are no constant post-mortem appearances. The muscles of the paralysed extremity are usually found flaccid, of a cream colour, and the subject of fatty degeneration.
Fatal Dose.—Sugar of lead is not an active poison, recovery having taken place after one ounce had been swallowed.
Fatal Period.—Uncertain.
Treatment.—The stomach should be emptied by means of the pump or syphon tube, followed by the free administration of the sulphates of soda and magnesia. The carbonates should not be given, the carbonate of lead being poisonous. Vomiting should be promoted, and a powerful cathartic administered. Albumen and milk should also be given, as these precipitate the oxide. In the chronic form of poisoning, the iodide of potash and aperients, notably the sulphate of magnesia, should be administered. Dixon Mann does not consider that iodide of potash is of any value as an eliminator of lead, as the latter forms a stable compound with the tissues. Sulphur baths are also useful in removing the lead from the system. Lately the galvanic bath has been tried with great success. By way of prophylaxis, it has been recommended that all those engaged in lead manufactories, or who are obliged to handle this metal frequently, should partake largely of lemonade made with sulphuric acid, should not take their meals in the factories, or without well washing the hands.
Chemical Analysis.—When the solid acetate is heated on platinum foil, it melts, then solidifies, becomes dark in colour, and gives off fumes of acetic acid.
The following are the liquid tests for lead in solution:
1. Dilute sulphuric acid gives a white precipitate of the sulphate, which is insoluble in nitric, but soluble in hydrochloric acid, in excess of caustic potash solution, and in ammonium acetate solution.
2. Solution of potassium iodide gives a yellow precipitate, soluble in boiling water and caustic potash solution.