(56 Select Plants for Industrial Culture and 



Ricinus communis, Linn6.* 



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 Caudolle in North-Eastern Africa. 

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

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

 as a summer-plant even to lat. 68 1' [Prof. Schuebeler], It was 

 well known to Egyptians four thousand years ago, and is also men- 

 tioned 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 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-tracts, and is evidently destined to be in countries 

 with cheap labour 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 applica- 

 tion 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 

 proceeded 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 techno- 

 logical purposes, the seeds may be pressed and prepared by various 

 methods under application of heat and access of water. For lubrica- 

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

 dissolres 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 

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

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

 nizes 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 



