R io in u s c om m u n is , Linné.*
The Castor-Oil Plant. Spontaneous in the tropical and subtropical
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. A t
Christiania it grew to 12 feet in height and bore fruit, and it is reared
as a summer-plant even to lat. 68° 7' [Prof. Sclmeboler]. I t was
well known to Egyptians four tliousand years ago, and is also mentioned
in the writings of Herodotus, Hippocrates, Dioscorides,
Theophrastos, Plinius and other ancient physicians, philosophers and
naturalists. Tlie easy and rapid growth, the copious seeding and the
early return of produce render this important plant of high value iu
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 liurtful
to pastoral interests ; but it may become an important plant also for
culture iu desert-tracts, and is evidently destined to be in countries
with clieap labour one of the most eligible plants to furnisb oil for
tecbnioal uses, partioularly for lubricating macliiiiery, irrespective of
the value of its oil for medicinal purposes. Cil used also for dressing
some kinds of leather. The scalded leaves, applied externally, have
long been known as a powerful galactagogue ; tlie foliage is also in
use as an emmenagogue ; tlie 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 bo 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 décantation and some process of filtration it
is purified, bnt it should never be long exposed to air and light. For
obtaining oil, to be used for lubricating of machinery or other technological
purposrs, the seeds may he 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 (his kind may
liecome valuable for various technical purposes, and afford some test
for the pureness of the oil. I f pressed under heat it will deposit
margaratiu. 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 a t the same time obtained,
which will probably become of industrial value. These facts are
briefly mentioned here merely to explain, th a t tlie value of this easily
produced oil is far more varied (han is generally supposed ; aud 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 isooetic aoid
(a glycerid). _ The oil contains also a non-crystailiue acid, peculiar
to It (neinoleio aoid). For the production of a particular kind of silk
the Ricinus-plant is also important, inasmuch as the hardy Bombyx
Arnndi requires the leaves of this bnsh for food. I t also helps to
drive mosqmtoes away. Pastoral animals must strenuously be kepi
away from the Ricinus. Even a few of the seeds, if swallowed, will
produce poisonous effects. The import of castor-oil in 1886 into
Britain was 175,813 cwt., worth £244,675. Into Victoria were
during 1887 imported medicinal oil to the value of £3,710 and lubri-
cation-oil worth £33,883. In the “ Chemist and Druggist” it is
stated, that Britain latterly used 900,000 gallons a year, worth crudely
£160,000. India exported in 1889-90 as much as 2,665,000 gallons
of Castor-oil aud 45,000 tons of seed [Dr. G. W a tt]. In countries
with a high labour-rate the competition with India also as reo-ards the
castor-oil industry will be difficult. But if riiralisis can be induced,
to rear the plant extensively and to offer the seeds cheaply, maiiufac-
tiirers would readily set up oil-mills.
R o b in ia P s e u d a c a c ia , Linné.
The North-American Locust-Acacia, ranging from Alleghany to
Arkanras. Height reaching 90 feet. Hardy to lat. 63° 26-' in Norway.
The hard and durable wood is in use for a variety of purposes
and particularly eligible for treenails, axletrees and turnery; strength
greater than th a t of the British oak, weight lighter [D. J . Browne]
The natives used the wood for their bows. The tree is of rapid
growth, and attains an age of several hundred years. A tree raised
in 1635, ill the Paris Jardin des Plantes, is still alive. One planted
in 1721 a t Britz near Berlin is still in a very flourishing state. I t
may be planted closely for timber-belts and hedge-shelter on farmlands.
I t IS one of the best trees for renovating exhausted laud and
for improving poor soil. Also a bee-plant. Reoommended as one of
the easiest grown of all trees on bare sand, tliough standing in need
of twice as much mineral aliment as Pinus silvestris and nearly as
much as poplars. I t pushes through shifting sand its spreading
roots, which may attain a length of seventy feet. I t will maintain
its hold in hollows of drifts, where even poplars fail [Wessely]
Will succeed on somewhat saline soil [Th. Kessall]. One of the few
among introduced kinds of trees which have thriven ou the outer
barren hills of the Punjab [W. Gollan]. , The roots are poisonous,
ih e allied E, viscosa (Ventenat) attains a height of 40 feet.
R o c c e lla t in c to r i a , De Candolle.
Canary-Islands, Azores, also iu Western and Southern Europe
and North-Ameriea. This lichen furnishes the litmus, orseille or
orchil for dyes and chemical tests. I t is a question of interest,
2 H 2