These do not neutralize acids, so are not locally antacid; but in the blood and tissues they break down into alkaline carbonates, and as the Co2 is exhaled increase the alkalescence of the blood. They are, therefore, systemic alkalinizers. These compounds are the acetic, citric, and tartaric salts of potassium, sodium, and lithium.

The potassium and sodium acetates, Kc2h3o2, NaC2H3O2, and the potassium, sodium, and lithium citrates, K3-,Na3-,Li3,-C6H5O7, are freely soluble in water. Potassium bitartrate, or cream of tartar (Khc4h4o6), is of acid reaction, and soluble in 200 parts of water. Potassium and sodium tartrate, or Rochelle salts (KNaC4H4O6), is very feebly alkaline and is soluble in 1.2 parts of water.

The acetates are readily absorbed, and are alkalinizing and diuretic. Dose, 30 grains (2 gm.).

The citrates and tartrates are absorbed with some difficulty, and, as a consequence, are more or less cathartic. A portion, however, is absorbed, and this acts as an alkalinizer and diuretic. After very large doses slight amounts of both salts have been recovered from the urine.

In the laboratory tartrates are employed to produce a tubular or tubulo-glomerular nephritis, but from doses taken by humans such an effect does not occur, and Post demonstrates that even in nephritis there is no contraindication to their use.

The citrates (see Citric Acid), through their affinity for calcium, will retard or prevent the coagulation of the blood and the rennin clotting of milk. They have been employed without any decided success in the late weeks of typhoid fever to lessen the tendency to thrombosis. Lithium citrate, in the form of effervescing tablets, each containing 5 grains (0.3 gm.), has been much employed to make a palatable effervescing alkalinizing drink. One tablet may be dissolved in a glass of water. Sodium citrate has been used in infant feeding, one grain (0.06 gm.) to each ounce (30 c.c.) of milk to reduce the density of the curd, and two grains (0.12 gm.) to an ounce (30 c.c.) to prevent completely the rennin clotting. In blood transfusion it is added to the blood in amounts to make 0.2 per cent. which effectually prevents clotting for half an hour.

Potassium bitartrate (cream of tartar) is not readily soluble in water. It forms Rochelle salts in the duodenum, and is laxative. It is a constituent of Imperial drink. (See Citric Acid.)

The hospital"A. B. C. mixture" is an aqueous solution of which each teaspoonful contains 5 grains (0.3 gm.) each of the acetate, bicarbonate, and citrate of potassium.