FOR VICTORIAN INDUSTRIAL CULTURE. 



203 



water. Castor-oil is usually bleached simply hy exposure to 

 solar liglit, 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 technic purposes, and afford some tests 

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

 depose margaritin. Heated in a retort about one-third of the 

 oil will distil over, and a substance resembling india-rubber 

 remains, which saponises with alkalies. Other educts are at 

 the same time obtained, which will likely become of indus- 

 trial 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 chemic compound of Castor-oil 

 is the crystalline Isocetin-acid (a Glycerid). The oil con- 

 tains also a non-crystalline acid peculiar to it (Ricin-acid). 

 For the production of a particular kind of silk the Ricinus- 

 plant is also important, inasmuch as the hardy Bombyx 

 Arrindi requires for food the leaves of this bush. The value 

 of Castor-oil imported in 1871 into Victoria was according 

 to the Customs returns not less than £23,755. Even a few 

 of the seeds if swallowed will produce poisonous effects. 



Robinia Pseudacacia, Linne. 



The North- American Locust-Acacia. Height to ninety feet. 

 The strong hard and durable wood is for a variety of purposes 

 in use, and particularly eligible for tree-nails, axle-trees, 

 turnery. The natives used the wood for their bows. Tree of 

 rapid growth, and attains an age of several hundred years. 

 It may be planted closely for timber-belts and hedge-shelter 

 on farm-lands. It is one of the best trees for renovating 

 exhausted land and for improving poor soil. The roots are 

 poisonous. The allied R. viscosa attains a height of forty feet. 

 No less than four arborescent Robinias are recorded from 

 Juan Fernandez. 



Roccella tinctoria, Candolle. 



Canary Islands, Azores, also in Middle and South Europe and 

 North Africa. This Lichen furnishes the Litmus, Orseille or 

 Orchil for dyes and chemical tests. It is a question of 

 interest, whether it could be trans-located and naturalised on 

 the cliffs also of our shores. Other dye-lichens might per- 

 haps still more easily be naturalised; for instance, Lecanora 



