in Extra- Tropical Countries. 327 



known to Egyptians four thousand years ago, and is also mentioned 

 in the writings of Herodotus, Hippocrates, Dioscorides, Theophrastos, 

 Plinius and other ancient physicians, philosophers and naturalists. 

 The easy and rapid growth, the copious seeding, and the early return 

 of produce render this important plant of high value in the warm 

 temperate zone, more particularly as it will thrive on almost any soil, 

 and can thus be raised even on arid places, without being scorched by 

 hot winds. Recently recommended for staying bush-fires and for 

 keeping off noxious insects and blights from plantations. It may 

 thus become an important plant also for culture in desert-tracts, and 

 is evidently destined to be in countries with cheap labor one of the 

 most eligible plants to furnish oil for technical uses, particularly for 

 lubricating machinery, irrespective of the value of its oil for 

 medicinal purposes. The scalded leaves, applied externally, have 

 long been known as particularly active on the mammary glands as a 

 powerful galactagogue; the foliage is also in use as an emmenagogue; 

 the root-bark has purgative properties. The seeds contain about 50 

 per cent. oil. To obtain the best medicinal oil, hydraulic pressure should 

 be employed, and the seeds not be subjected to heat; the seed-coat 

 should also be removed prior to the extracting process being proceeded 

 with. A screw-press suffices however to obtain the oil for ordinary 

 supplies. By decantation and some process of filtration it is purified. 

 For obtaining oil to be used fer lubrication of machinery or other 

 technological purposes, the seeds may be pressed and prepared by 

 various methods under application of heat and access of water. For 

 lubrication it is one of the most extensively used of all oils. Castor- 

 oil is usually bleached simply by exposure to solar light, but this 

 procedure lessens to some extent the laxative properties of the oil. 

 It dissolves completely in waterless alcohol and in ether, and will 

 become dissolved also in spirit of high strength, to the extent of 

 three-fifths of the weight of the latter. Solutions of this kind may 

 become valuable for various technical purposes, and afford some test 

 for the pureness of the oil. If pressed under heat it will deposit 

 margaritin. Heated in a retort about one-third of the oil will distil 

 over, and a substance resembling india-rubber remains, which 

 saponizes with alkalies. Other educts are at the same time obtained, 

 which will probably become of industrial value. These facts are 

 briefly mentioned here merely to explain, that the value of this easily 

 produced oil is far more varied than is generally supposed; and this 

 remark applies with equal force to many other chemical compounds 

 from vegetable sources, briefly alluded to in this present enumerative 

 treatise. The seeds contain also a peculiar alkaloid ricinin. The 

 solid chemical compound of castor-oil is the crystalline isocetic acid (a 

 glycerid). The oil contains also a non-crystalline acid, peculiar to it 

 (ricinoleic acid). For the production of a particular kind of silk the 

 Elcinus-plant is also important, inasmuch as the hardy Bombyx 

 Arrindi requires the leaves of this bush for food. Even a few of the 

 seeds, if swallowed, will produce poisonous effects. The root-bark 

 has also been drawn into use as a purgative (Bernays). 



