494 EUPHORBIACE^E. 



18 species. There are about 192 known genera, and upwards of 

 2500 species. Examples Euphorbia, Hippomane, Hura, Acalypha, 

 Croton, Jatropha, Ricinus, Phyllanthus, Buxus. 



1015. The plants of this order are acrid and poisonous. These 

 properties reside especially in their milky juices, which are contained 

 in laticiferous vessels (fig. 66), in which the movements of Cyclosis 

 were observed by Schultz (^[ 262). 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 an irritating nature. 



1016. The milky juice of many species of Euphorbia is caustic, and 

 has been used for destroying warts, and causing vesication. At other 

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

 The root of Euphorbia Ipecacuanha has been employed as a substitute for 

 Ipecacuanha. The resinous substance called Euphorbium is procured, 

 in all probability, from two African species, Euphorbia officinarum and 

 antiquorum, as well as from E. canariensis, a native of the Canary 

 Islands. 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, Sandbox-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. Mercurialis perennis, and annua, pro- 

 duce vomiting and purging. 



1017. Many important medicinal oils are furnished by the plants 

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

 munis (Palma Christfy, a plant with peltate-palmate leaves (fig. 146), 

 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 substance 

 called Palmin. The oil acts as a mild laxative. Besides this com- 

 paratively bland oil, there exists in the seed a powerfully cathartic 

 constitutent, 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 Croton Tiglium, 



