EUPHOKBIACB^. 581 



p. 21), in -which the movements of Cyclosis were observed by Schultz 

 (p. 146). In many cases the elaborated sap 'contains caoutchouc 

 and resin. The acrid 'properties of the order are also found in the 

 seeds, many of which yield oils, both of a bland and of la^ irritating 

 nature. ' 



The mUky juice of many species of Euphorbia is caustic, and has 

 been used for destroying warts and causing vesication. At other 

 times the juice has been used for its purgative and emetic properties. 

 The root of Euphorbia Ipecacuanha has been employed as a substitute 

 for Ipecacuan. The resinous substance called Euphorbium is pro- 

 cured from Euphorbia resinifera, a native of Morocco. It is a leafless 

 plant like a Cactus, attaining a height of six or more feet. The stem 

 is fleshy and quadrangular, and on its angles are produced at intervals 

 spines which represent stipules. The resin is a powerful irritant, 

 and has been used as a vesicant. It causes great irritation of the 

 mucous membrane when applied to the nostrils and eyes, and it acts 

 as a cathartic when taken internally. Many species of Euphorbia 

 yield resins of a similar nature. The juice of Hippomane Mancinella, 

 Manchineel, is very acrid and poisonous. When applied to the skin 

 it excites violent inflammation, followed by ulceration. The juice of 

 Hura crepitans, Sand-box-tree, or Monkey's dinner-bell, is also very 

 acrid. The fruit of this tree is composed of numerous 1-seeded cocci, 

 which, when dry, separate from each other with great force. Mer- 

 curialis perennis, and annua, produce vomiting and purging. 



Many important medicinal oils are furnished by the plants of this 

 order. Castor-oil is expressed from the seeds of Ricinus communis 

 {Palma Christi), a plant with peltate-palmate leaves (fig. 161, p. 88), 

 which is found native in Greece, Africa, and the East Indies, and is 

 cultivated in the West Indies, as well as in North and South America. 

 In the temperate and more northern parts of Europe the plant is a 

 herbaceous annual, of from three to eight feet high ; in the more 

 southern parts it becomes shrubby, and even attains a height of twenty 

 feet ; while in India it is often a tree thirty or forty feet high. The 

 best oil is got by expression from the seeds, without heat, and is called 

 cold-drawn Castor-oil It is entirely soluble in alcohol, and, by the 

 action of hyponitrous acid, it is converted into a solid yellow sub- 

 stance called Palmin. The oil acts as a mild laxative. IBesides this 

 comparatively bland oil, there exists in the seed a powerfully cathar- 

 tic constituent, which remains behind when the oil is expressed, and 

 which is destroyed or evaporated under the process of ebullition. 

 Croton-oil is obtained by expression from the seeds of Groton Tigliwm 

 [Tiglium officinale), an Indian and Asiatic shrub. It acts as an irri- 

 tant purgative in the dose of one drop. In large doses it is a dan- 

 gerous poison. When applied externally it produces pustules. Other 

 species of Croton, as G. Pavana and Eoxburghii, yield a purgative oil. 



