This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol2", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
This is the bark of the root of Melia Azedarach, pride of China, or pride of India, a large and beautiful tree, indigenous in Asia, but naturalized in the southern parts of the United States, where it is cultivated as an ornament to the towns and villages.
Though other parts of the plant are not without anthelmintic properties, the bark of the root is the most active, and the only portion recognized by our national pharmaceutical code. it has a bitter, nauseous taste, and yields its properties to boiling water. Being considered most efficacious in the recent state, it is seldom kept in the shops; and, therefore, has been little employed in the Northern States. But in the South it is considerably esteemed, and has been much used in some districts.
In relation to its effects on the system, the bark generally operates on the bowels in the regular doses, and, if these be exceeded, sometimes proves emetic. it is said also, when largely taken, to produce narcotic effects similar to those produced by spigelia. it is usually administered in decoction; four ounces of the fresh root being boiled with two pints of water to a pint, of which the dose for a child from two to four years old is a tablespoonful every two hours till it purges, or night and morning for several days, and then followed by a cathartic.