Like the citrate just mentioned, this has for one ingredient citric acid, obtained from lemon or lime-juice. This is neutralized by potassium (an alkaline metal) as it may be also by magnesium; in each case making what chemists call salt.

Citrate of potassium acts very slightly, if at all, on the bowels. It is used in solution to cool the system and promote secretion from the skin and kidneys in fever. One way of taking it is in neutral mixture (one drachm of this citrate in four fluid-ounces of water); of which the dose is a tablespoonful every two or three hours. Another way is in effervescent solution. (See effervescing draught.)