As a purgative it operates mildly, and may be given to the youngest infant; if from two to twelve months old, from three to six grains; for children above that age, the dose may range from ten grains to twenty. Its operation, however, is much quickened by the addition of magnesia; both of which are more effective when thus united than when given separately. The following form, in a costive and flatulent state of the bowels, will be found useful[FN#19]; a tea-spoonful or more may be given every three or four hours until the desired effect is obtained:-- Powdered rhubarb, half a drachm; Magnesia, two scruples; Compound spirits of ammonia, twenty drops; Dill water, two ounces; Simple syrup, two drachms. [FN#19] This may be made up and kept in the nursery for a long time without spoiling. Rhubarb, mixed with flour and warm water, may be made into a poultice, and applied to the abdomen of a child that obstinately refuses to swallow medicine, and it will be found to produce the same effect as if the medicine had been taken into the stomach; it will purge briskly. THE LAVEMENT. This is an excellent nursery remedy when the bowels are obstinately costive. It may then be employed as a substitute for medicine, a protracted and frequent use of which (even of the mildest aperients) is apt to injure the digestive functions, and to give rise to some degree of intestinal irritation. Lavements, however, like aperient medicine, must not be resorted to for a long time together; for whilst the latter irritate, the former most certainly tend, after a long continued use, to debilitate the bowels, and thus render them less than ever disposed to act for themselves. They are an excellent occasional remedy. The simplest form of an aperient enema, is warm water; but barley- water, or thin gruel, or even milk and water, are to be preferred at all times, as they are of a more bland and less irritating nature. If it be desirable to increase the strength of the injection, castor oil may be added. The proportions of fluid which are necessary for the different stages of life, under ordinary circumstances, maybe stated as follows:--An infant at its birth requires about one fluid ounce; a child between the age of one and five years, from three to four fluid ounces; and a youth of ten or fifteen, from six to eight fluid ounces.