Untoward Action. - 3-5 grains (0.19-0.32 Gm.) have produced nausea and gastric oppression, while if the zinc salt reaches the intestines diarrhea results. When taken on a full stomach the salts form an insoluble albuminate which undergoes the regular digestive process.

Repeated small doses, 3 grains (0.19 Gm.), have produced gastric oppression, eructations, slight confusion of thought, dizziness, bodily exhaustion, thirst, gastralgia, vomiting, and diarrhea. Zinc dyscrasia may follow, characterized by obstinate constipation, emaciation, and anemia.

Poisoning. - Continued use or excessive doses of zinc will produce poisoning, with symptoms resembling those of lead-poisoning.

Chronic Zinc-poisoning. - Among zinc workers there is a type of poisoning known as "zinc-founders' fever" or ague. The attacks frequently are acute. After pouring a mold the worker may have a sense of general distress, with backache and irregular muscular pains and lassitude. There is no disturbance of the pulse or of temperature. Shortly following this chills may develop, the pulse is increased to 100 or 120, and there are cough, pain in the chest, and headache. Profuse perspiration marks the climax of the attack, and the patient has labored sleep and recovers.

It is not improbable that the accompanying salts of arsenic and lead, always found in commercial zinc, are responsible, in part at least, for some of these symptoms.

Treatment of Poisoning. - Chemical antidotes are the bicarbonates of soda and potassium. Flour and water, soapsuds, and milk are also beneficial. Morphine given hypodermically relieves the vomiting. Laxatives and potassium iodide may serve later to assist in eliminating the zinc.

Therapeutics. - Zinc Oxide. - Externally and Locally. - The ointment or powder is used in chronic eczema, intertrigo, burns, fissured nipples, anal fissure, ulcers, and skin diseases. In combination with linseed oil the oxide has also been used in erysipelas. The drug has proved useful as an injection in leucorrhea.

Internally. - Associated with bismuth, sodium bicarbonate, or belladonna, it is very effective in diarrhea - particularly the summer diarrhea of children - and dysentery.

It is a most excellent remedy for colliquative sweating and the sweating of phthisis, and also serves to check the profuse secretion of bronchorrhea, although its use may occasion disordered digestion, since zinc is but sparingly soluble.

The oxide is valuable in gastralgia.

Zinc Acetate. - It is used only externally and as an injection in gonorrhea and leucorrhea. In conjunctivitis it is useful as a collyrium.

Zinc Sulphate. - Externally and Locally. - The external use is chiefly in weeping eczema, pruritus, and ulcers. Locally it is of service as a wash in ophthalmia and conjunctivitis, and as an injection in gonorrhea, leucorrhea, vulvitis, and otitis. It is also used in gangrenous stomatitis, cancrum oris, and as a gargle in enlarged tonsils and relaxed sore throat. In nasal polypi the powder is insufflated, the solution being applied to the stump after removal of the polypus. It dries up soft tumors near the vagina, anus, and female urethra.

Internally. - Its chief use is that of an emetic after ingestion of poison, irritating foods, and especially narcotics, as well as where the air-passages are obstructed, as in croup and diphtheria.

It acts as an astringent in chronic diarrhea and dysentery when associated with opium and ipecac.

Zinc Carbonate. - This preparation is used only externally, for blisters, weeping eczema, and intertrigo. It is employed in the form of a powder, but generally as an ointment - cardamine ointment.

Zinc Iodide. - This salt is but little used, but is of some value as a gonorrheal injection, as an application to enlarged and indurated tonsils, and in scrofulous glands.

Zinc phosphide and zinc valerianate are used only for the benefit derived from the phosphorus and valerianic acid, and may properly be omitted here.

A long list of newer compounds of zinc have been given by the synthetic chemists. Some are of service, but they should be employed with understanding. The most important are the borate, chrysophanate, cyanide, gynocardate, hemol, zinc ichthyol, sulfonate, permanganate, salicylate, sozo-iodolate, stearate, subgallate, and sulphocarbolate.

Administration. - Externally the powder or ointment of zinc oxide is used, or the drug may be mixed with powdered starch, lycopodium, or acacia. Before applying these preparations it is well to wash the parts with a weak solution of carbolic acid.

Internally, 1/4 grain (0.01 Gm.) zinc oxide and 3 grains (0.19 Gm.) sodium bicarbonate are given in diarrhea, or, if preferable, bismuth subnitrate 10 grains (0.64 Gm.), pepsin (Sheffer's) 3 grains (0.19 Gm.), and zinc oxide 1/2-1 grain (0.03-0.06 Gm.), with a little opium added.

As an injection a combination of 10 grains (0.64 Gm.) each of zinc sulphate and lead acetate is used, the two salts interacting and producing lead sulphate - which is precipitated and insoluble - and zinc acetate.

Locally and externally the dry powder of zinc sulphate is used, or a mixture of zinc sulphate 10 grains (0.64 Gm.), aqua rosae 4 ounces (118.29 Cc), and glycerin 1 dram (4.0 Cc), as a lotion. As an injection it is associated with lead acetate, forming the zinc acetate and lead sulphate. In ophthalmia neonatorum zinc sulphate 5 grains (0.32 Gm.), morphine sulphate 3 grains (0.19 Gm.), and aqua rosae 1 ounce (30 Cc), perhaps with atropine added, form an excellent mixture.

Internally, in dyspepsia 1-2 grains (0.06-0.12 Gm.) may be given, and for intestinal affections 1 grain (0.06 Gm.) each of the sulphate, powdered opium, and ipecac three times daily. To produce emesis 5 grains (0.32 Gm.) are sufficient.

The collyrium consists of 1/2 grain (0.03 Gm.) of the salt in 1 ounce (30 Cc.) of rose water.