Given by the mouth glycerin produces purging if large doses are administered, and has the same action if only a small quantity be introduced into the rectum.
There are various systems of purging refined, or socalled refined, sugar in centrifugals, all designed with a view of obtaining the sugar in lumps or tablets, so as to appear as if it had been turned out from moulds and not from centrifugals, and great ingenuity and large sums of money have been spent in perfecting these different systems, with more or less happy results.
It hardly affects the small intestine, but markedly stimulates the muscular coat of the large intestine, causing purging in about fifteen hours.
Several members of the order are used medicinally for the strong purging properties of the milky juice (latex) which they contain; scammony is the dried latex from the underground stem of Convolvulus Scarnmonia, a native of the Levant, while jalap is the product of the tubercles of Exogonium Purga, a native of Mexico.
On some plantations making sugar for particular markets and use in refineries it is the custom to make only one class of sugar, by boiling the molasses produced by the purging of one strike with the sugar in the next strike.