Lemon, Citrus Limonum, the peel and oil official in the U. S. Citrus aurantium, Sweet Oranges (peel), official in the V. S., and the fruit in Spain, the oil in the U. S. and other countries. Citrus vulgaris, Bitter Oranges, is official (peel, oil, unripe fruit, blossoms, leaves, and oil of flowers) in numerous countries. The volatile oil from the flowers is known as oil of neroli. Lemon seed is official in Spain. Citrus acida, Lime, and Citrus decumana, Grape Fruit, are also employed in medicine.

Citrus juices are tonic, refrigerant, and antiscorbutic. The uses are too familiar to require comment except that the fruit juices are of great value in typhoid and other fevers. Orange juice is largely used in hospital wards and should be more used in the home treatment of the sick. It is of interest to note that citrus fruit is, in the oxidizing process of digestion, an agent serving to help alka-linize (or render less acid) the urine. Hence conditions of acidosis may be benefited by eating oranges, of course not neglecting the administration of bicarbonate and other indicated drugs. Scorbutic children, especially the bottle-fed, may be wholly cured by administering orange juice. The hemorrhagic diathesis, and certain cases of pruritus, are benefited by citrus juices. Hoarse throat is treated with lemon juice, as are many external conditions. The free use of lemons is advocated as a prophylactic against gastroenteric troubles in summer. Grape fruit contains a bitter which is a gastric tonic and is said to aid in the treatment of rheumatism.