Hydrargyrum cum creta, calomel, and blue-pill are very similar in action. Calomel, being insoluble, probably escapes solution and combination in the stomach, and is decomposed by the alkaline contents of the small intestine, the oxide of mercury being precipitated. It follows, from this reaction, that the effects of blue-pill and calomel must be similar, and in practice it is found that they correspond closely therapeutically. Salivation more frequently results from the use of blue-pill than from the other mercurials; and calomel comes next in point of activity in this respect.

The corrosive chloride, the red iodide, and the cyanide, are powerful irritant and corrosive poisons. When a poisonous dose of corrosive sublimate has been swallowed, the mucous membrane of the mouth has usually, but not invariably, a whitish, glazed appearance, as if it had been washed over with a strong solution of the nitrate of silver. A sense of constriction of the throat and a strong styptic and metallic taste are experienced. The toxic symptoms follow in a few minutes the ingestion of the poison. Usually, violent pain is felt in the abdomen, but this is not invariable. Vomiting follows, and the vomited matters consist at first of the contents of the stomach, and afterward of mucus streaked with blood. There are usually purging, tenesmus, intestinal cramp, and not infrequently dysenteric discharges

These evidences of violent gastro-intestinal irritation are accompanied bv small, weak pulse, coldness of the surface—but sometimes by a swollen and flushed face—sighing respiration, syncope, insensibility, or convulsions. If the patient survive a few days, ptyalism may occur.

The following are the symptoms of chronic poisoning stated in the most concrete form: abdominal pains; nausea; vomiting; dysenteric diarrhoea; general weakness, trembling, or paralysis, and other nervous affections; ptyalism; fever; emaciation, etc. There sometimes occurs a blue line along the margin of the teeth, not unlike that produced by lead. Suppression of urine is a not infrequent symptom in acute poisoning, and albuminuria is very often present in cases of chronic mercurialismus.

The corrosive chloride and the red iodide of mercury are the most powerful antiseptics and germicides now available. Their germicide powers have been made the subject of investigation in the only way that such a question can be determined—by ascertaining the degree and character of their effects on cultures of the pathogenic organisms. To Miguel, De la Croix, Bucholtz, and others in Europe, and to Sternberg and Welch in this country, we owe the very accurate knowledge now possessed of the character and limits of the germicide power. Any difference that exists between the chloride and iodide, in respect to their power to destroy disease-germs, is in favor of the latter (Miguel). An effective germicide is destructive not only of the organism but of its ova. Experience has demonstrated that the germ—the microbe—may be killed and yet the ova resist the action of the germicide and hence pullulation goes on as actively as before. No antiseptic is entitled to be so designated unless its power is equal to the destruction of the organism and of its ova also.