When a quantity of any one of the preparations has been swallowed, sufficient to produce severe irritation or inflammation of the stomach, an emetic of ipecacuanha should be immediately administered, along with sulphate of magnesia, or other harmless sulphate, as an antidote, and with free dilution. The salt acts by forming with the preparation of lead the insoluble and comparatively innocent sulphate of that metal. After the stomach has been thoroughly evacuated, a cathartic dose of the sulphate of magnesia or of soda should be given, to decompose and carry out of the bowels any of the poison which may have entered them. The remaining treatment must consist of measures calculated to remove any irritation or inflammation that may have been produced; as the use of opiates, demulcent drinks, counter-irritation to the epigastrium, and, if necessary, leeching.

* A very interesting account has been published of extensive lead-poisoning, affecting upwards of 200 persons in a limited community in Orange Co., N. York, which was found to be owing to the use of flour obtained from a certain mill, in which defects in the surfaces of an old pair of stones had been obviated by filling the cavities with melted lead, whereby particles of the metal, separated in the attrition, had become mingled with (he flour. (Am. Journ. of Pharm., July, 186G, p. 366, from N. Y. Tribune, June 2.) Even the use of cosmetics containing lead is believed to have been a source of the disease; and a case of the kind was observed by Dr. W. Couzins, of London. (Med. T. and Gaz., Sept. 1864.) - Note to the third edition.

† A very slight degree of impregnation with lead is sufficient to render water poisonous, when used as an habitual drink. In one instance where a whole village suffered from this cause, Mr. Herapath found the proportion of lead not to exceed half a millionth of the weight of the water. Indeed, the proportion is so small as, in the dilute state, to be insensible to the test of hydrosulphuric acid. Under such circumstances, Mr. Herapath evaporates a portion of the water to dryness, treats the residue with nitric acid, and, dissolving the product in a small proportion of water, passes hydrosulphuric acid through the solution. The smallest proportion is thus detected by the dark colour produced; the nitrate being more sensible to the test than the bicarbonate, in which state the lead is usually held in the water. (Pharm. Journ. and Trans., xviii. 618).

The peculiar poisonous effects of lead require a different treatment. In such cases the metal has entered the blood, and is probably lodged in the various tissues. The indications are to obviate the pathological conditions produced, and to eliminate the poison from the system. Sulphuric acid and the different sulphates have been recommended as antidotes; but it is obvious that they are not calculated to correct the action of the absorbed poison in this way; for, if absorbed themselves, they could act only by converting the combination of lead, existing in the blood or the tissues, into a sulphate, which, from its comparative insolubility, would resist elimination, and might continue to exercise a noxious influence, if fixed in the solids. It is only by operating on any portion of the poison existing in the alimentary canal, that they could do good in this way; and when there is reason to suppose that such a condition of things exists, they should be employed. The sulphurets have a similar antidotal power; but, from their more irritant properties, they are seldom given internally. Used externally in the form of bath, they prove advantageous by converting into the inert sulphuret any preparation of lead that may adhere to the surface; and probably still more so, by disposing, through their chemical agency, to an elimination, upon the surface of the body, of the lead which may be circulating in the blood. It is asserted that, in cases of saturnine impregnation of the system, the use of these baths is followed by the production, upon the skin, of a dark matter, which is the sulphuret of lead. The result may, it is true, be ascribed to the excretion of the lead by the skin, through the unaided powers of the system; and the antidote may act simply by forming a sulphuret with the excreted metal. Even in this case, it might prove useful by putting the poison into a condition unfitting it for reab-sorption; but the probability, I think, is, that it has a positive power of elimination through its affinity for the lead in the blood-vessels, acting through the epidermis and the capillary walls; and that thus the poison is withdrawn much more rapidly than it would be by the excretory power of the skin alone. The bath may be made by dissolving four ounces of sulphuret of potassium in thirty gallons of warm water, in a wooden tub. After immersion, the dark coating formed should be removed from the surface by scrubbing with a stiff flesh-brush, with soap and water; after which the patient should be again immersed, and the process repeated so long as any obvious discoloration of the skin is produced. In a short time, a renewal of the bath will be found again to discolour the skin. The measure, therefore, should be repeated twice a week, and not abandoned until this effect ceases to be produced, which may not happen for many weeks.

Another method by which lead may be eliminated from the system, is through the agency of some body, which, received into the blood, and circulating with it, may be brought into contact with the insoluble compound of lead in the tissues, and, rendering it soluble in the blood, may enable that fluid to take it up, and discharge it through the different emunctories. Iodide of potassium, which, in an alkaline solution, has the property of dissolving lead, was recommended for this purpose by M. Melsens, and was found by him to be one of the most efficacious remedies in lead-poisoning. According to this theory of its action, evidences should be presented of the absence of lead in the urine or other excretions before the use of the iodide, and its presence afterwards. This evidence M. Melsens did not produce; but, subsequently to the publication of his memoir, Dr. E. A. Parkes, of London, found the requisite proof in a case which came under his notice (Brit, and For. Medicochlrurg. Rev., Am. ed., xi. 411); and Dr. II. S. Swift, of New York, has given an account of no less than twenty-three cases, in which the iodide was used very advantageously in obstinate lead-poisoning, and in many of which lead was detected in the urine after the use of the remedy, though in no instance could it be discovered previously. (N. Y Med. Times, iii. 145.) M. Melsens found, in his experiments on animals, that the poisonous effects of the lead were increased when the iodide was early employed, probably in consequence of its rendering the poison in the alimentary canal more soluble, and consequently more readily absorbed; and it is not impossible that the liberation of the lead from certain tissues, and its reintroduction into the blood, may occasionally, for a time, aggravate the symptoms. Dr. Swift noticed this in two out of twenty-three cases; but the aggravation was slight, and improvement was soon evinced. From five to twenty grains of the iodide may be given three times a day, and continued until the symptoms of poisoning cease. One evidence of improvement is the disappearance of the blue discoloration of the gums produced by the lead.