3i6 
THE TROPICAL AGRICULTURIST* [November i, 1887. 
before sowing can take place. For neither corn nor 
the castor oil shrub can stand the slightest frost, 
and their seed rot in the ground unless the latter 
is thoroughly warm. This condition is not fulfilled 
until after the rainy season is over. Of course, 
where natural rainfall is defective, artificial irrig- 
ation may be used, but this is never as effective as 
the former. 
Before starting any plantation of the castor oil 
plant, the amount of available moisture, either natural 
or artificial, must be thoroughly studied. 
The castor oil plant requires a very rich soil, if it 
is to yield an ample crop, as may be seen from the 
following composition of the ash of the seeds : — 
Lime 
88-38 
Magnesia 
733 
Oxide of iron 
0-89 
Phosphoric acid ... 
38-65 
Sulphuric acid 
;2'21 
Chlorine 
0-89 
Potassa 
29-52 
Soda 
8-75 
100-00 
Attention is called to the large amount of potassa, 
and particularly to the extraordinarily high percentage 
of phosphoric acid. The plant also requires a copious 
supply of nitrogen. Unless the cultivation is started 
on virgin soil manuring can scarcely be avoided, 
though it would be useless to expect everything from 
artificial enrichment of the soil. The latter must be 
naturally adapted to it. It must, besides, be neither 
too loose nor too dense; neither stiff clay nor loose 
sand answers the purpose. A clayey-sand or sandy- 
clay bottom or alluvial ground is most conducive, 
provided it is of sufficient depth and porosity. 
"While it would be the most rational method to ascert- 
ain the capabilities and requirements of a soil by a 
chemical analysis of it, made from time to time — 
and this should be done if at all possible — jet in 
many cases this will be impracticable. It is, therefore, 
of advantage to know a manuring compound which 
is likely to furnish all the required constitueuts, 
without doing harm by the presence of one or another 
in excess. Such a compound is produced by a 
mixture of 
Cotton seed ... ... 750 parts. 
Stable manure ... ... ... 750 „ 
Superphosphates... ... ... 500 „ 
If cotton seed cannot be obtained, the following 
may be used: — 
Cotton seed meal... ... ... 500 parts. 
Stable manure ... ... ... 1000 „ 
Superphosphate ... ... ... 500 ,, 
These substances are to be made into a heap under 
cover, and to be thoroughly moistened, in order to 
prevent overheating and to promote fermentation. 
After six weeks the mixture may be applied to the 
fields, from 1080 to 3000 pounds per acre, according as 
may be required. The soil must be turned deep as 
the roots of the shrub penetrate to a considerable depth. 
When the soil has been properly prepared sowing 
may commence. This should be done in the beginr 
ning of the rainy season, except where frosts are to 
be expected near its end, in which case the beginning 
of the hot season must be awaited. The next question 
to be decided is which variety is most suitable for 
the locality. If the common species be employed, 
which usually grows to the height of about 8 feet 
in tbe sub-tropics, the plants must be placed at 
intervals of 4 tent in all directions. Under the tropics 
the. shrub grows 2 or 3 feet higher ; the distance 
here must be 5 feet. If a still higher variety is 
chosen (such as Ricinus sanguineus), the distance 
should be extended to 8 feet. 
In planting out on a large field, supposing the dis- 
tance between the plants is determined at 5 feet, it 
id advisable to leave a space of 7 feet after every 
live rows of 5 feet apart, but only in one direcliou. 
This wider passage facilitates tho harvesting. 
The sced-bcans are soaked for twelve hours in 
liike-warrn water, then laid in pairs in tho market 
plaices, and covered with earth 1 inch high. As 
soon as the plants are 3 to 5 inches high, the weaker 
of the two plautlets is pulled out at every place. 
Sometimes four beans are planted at a time, and 
the two weakest ones pulled out, but this is . not to 
be recommended. If economy of 6pace is necessary, 
it is better to put the plants closer together, rather 
than to duplicate them in one place. 
The field requires only a repeated loosening of the 
soil with the cultivator, not with the plough, as 
this penetrates too deep and injures the roots. Hence 
even the cultivator must be adjusted at a rather 
slight depth. How often this operation should be 
performed depends on the weather. Four repetitions 
are usually sufficient. Of course, the soil in the 
immediate vicinity of the plant must be loosened 
with the hoe or rake. 
So far as known to the author, the castor oil plant 
is only attacked by one insect, the same as infests 
the tobacco plant ; all other insects shun it. In fact, 
the presence of the shrub appears to be a good agent 
to repel insects of all kinds. For this reason, probably, 
it is customary in some tropical districts to surround 
the field with several rows of castor oil plants, a 
practice that appears to deserve imitation. 
When the pods ripen, they turn brown, hard and 
brittle, and begin to burst. All pods do not ripen on 
the plant at the same time, but the ripening process 
proceeds from below upwards. Hence the harvest- 
ing must be done in several instalments. For this 
purpose it is quite enstomary to U6e a sort of sled, 
drawn by a docile horse or other animal, which is 
guided through the wider passages of the field, while 
the ripe capsules are collected at either side of it 
and thrown into the box of the sled. A smooth 
ground is previously prepared at a suitable place in 
the neighbourhood, and surrounded by a boar 1 fence 
4 to 5 feet high. Upon this place, which must be ex- 
posed the greater part of the dav to the hot rays of 
the sun, the capsnles are piled to a depth of 3 t« 4 
inches, and turned over with a shovel once each day. 
"With favourable weather, the capsules burst completely 
in four or five days. In order to separate still adher- 
ing seeds, a very light roller, drawn by an unshod 
horse, is rolled several times over the ground, the 
capsules being turned over before each new circuit. 
The capsules and beans are then put in one heap, 
and the latter separated from the former by a win- 
nower or by means of throwing with a shovel. 
The ground having been cleared, it is ready for 
the next crop, and this is continued until the harvest 
is over. The shrubs are then cut down and put in 
the compost heap. 
The clean beans are finally put in bags, and sold 
to the miller. 
In the East Indies the oil is extracted by crushing 
the beans between two rollers, the mass is packed 
into hempen sacks, and expressed by a screw-press. 
The oil is mixed with water, and the latter raised 
to boiling. This causes the impurities to rise to the 
top. The oil is next strained, bleached by exposure 
to the sun, and transferred into casks. In Oudh, 
the crushed beans are boiled with water, and the 
oil which rises to the surface gradually dipped off. 
In the United States, the usual process followed is 
to expose the beans in an oven for an hour to a dry 
heat, which has been found to facilitate the extraction 
of the oil. They are next transferred (in bags) to a 
strong screw-press, a»d the oil, as it runs out, imme- 
diately mixed with an equal measure of water. 
The mixture is boiled for an hour, which causes 
the coagulation and separation of the albuminoids con- 
tained in the oil. After cooling, the oil is drawn 
off and transferred to large zinc tanks, in which it 
remains eight hours. Finally, it is exposed to tho 
sun to bleach. One hundred pounds of beans yield 
about 18 quarts of oil. The finest oil is obtained 
by a process, which, according to the author, is only 
partially known. The beans are first passed through 
rollers in which their peel or skin is taken off, which 
contains an oil of disagreeable taste. They are then 
crushed, and either cold-pressed or extracted with 
alcohol. The oil is finally purified by contact with 
