Naturalisation in Extra- Tropical Countries. 421 



Ricinus communis, Linne.* 



The Castor-Oil Plant. Spontaneous in the tropical and sub- 

 tropical zones of Asia and Africa, but hardly in South-Europe, 

 originating according to A. de Candolle in North-Eastern Africa. 

 A shrubby, decorative plant, attaining the size of a small tree. At 

 Ghristiania it grew to 12 feet in height and bore fruit, and it is 

 reared as a summer-plant even to lat. 68 7 r [Prof. Schuebeler]. 

 It was well 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 recom- 

 mended for staying bush-fires and for keeping off locusts and other 

 noxious insects and blights from plantations ; also available for 

 some dye-processes. In warm climes this plant may spread beyond 

 control, and may then become hurtful to pastoral interests ; but it 

 may become an important plant also for culture in desert-tract, 

 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. Oil used also for dressing some kinds of 

 leather. The scalded leaves, applied externally, have long been 

 known as a powerful galactagogue ; the foliage is also in use as an 

 emmenagogue ; the root-bark has purgative properties. The seeds 

 yield about 25 per cent, oil, when pressed without application of 

 heat. 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 pro- 

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

 ordinary supplies. By decantation and some process of filtration 

 it is purified, but it should never be long exposed to air and light. 

 For obtaining oil, to be used for lubricating 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 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 



