May I, 189-.] Supplement io the Tropical AgricnlUirist.'" 817 
a given space of Inncl, wlien compared with fdlier 
food products. Its introduction to Ceylon is 
attributed to the Dutch, wlio by the way liiive 
tlie credit of having introduced many useful 
food products which are commonly grown in 
the villages at the present day. According to 
Dr. Ainslie, the manioc plant was brought to 
Ceylon from Alauritius by Governor Van der 
Graff in the year 1787 ; and thus it will be seen 
that the plant has been in cultivation in this 
Island for over a century. This plant, like the 
other plants of the same family, possesses acrid 
properties, in addition to its containing a 
small percentage of hydrocanic acid. The 
characteristic .smell of the cyanides being cpiite 
perceptible. 
It has been found that there are above thirty 
different varieties of manioc grown all over the 
world, but these are considered to be only 
slight variations of two distinct specie.s, Mcan'hot 
TJtilisimu and the M. A/pi, the bitter and the 
sweet manioc respectively. The former variety 
has certain poisonous properties in it, in a raw 
state, while the roots of the latter are quite 
sweet and harmless. These varieties could be 
distinguished from their outward aiipearanc(' by 
observing the leaves. The leaves of the liittor 
manioc have seven divisions, and the veins on the 
under surface are coloured red ; whilst the sweet 
manioc possesses leaves with five divisions of a 
pale green coloiw. 
So far as I have seen both these varieties are 
fo\ind in Ceylon, but the variety generally 
cultivated is a slightly modified type of the 
JatrnpJia Utilisima, the bitter manioc. 'In all 
countries this variety is jtreferred because it 
yields more abundantly. The Ititter indnciples 
and poisonous characters f)t its roots are re- 
moved by drying or boiling. 
The cultivation of the manioc plant is carrie<l 
on to a large extent in the AVestern and North- 
AVestern districts of Ceylon. In nuiny other 
districts it has rather a bad reputation as a food 
])i‘oduct on account of tlie poisonous properties 
which the fresh roots of some of the varieties 
possess, and on account of frequent deaths which 
occur by the careless use of the root. 
The manioc is grown both in chena lands 
and in new cleaiings for coconut. It forms a 
very paying subsidiary croj) along with the latter. 
The plant is propagated by cutting the stems 
wliich give out buds from almost every node. 
In cultivating manioc, the land is prepared by 
hoeing and burning. Shallow holes are made 
with a mamoty four feet ajiart, or sometimes 
five, and two pieC(>s of manioc, cuttings fi'om 
nine- to ten inches long are -1)1^06(1 in the hoh'S and 
slightly covered with eartli. These give out a 
large number of buds whicli grow witli much 
7 M])idity. In planting manioc advantage is takcm 
of a few .slight showers, but when growing 
tliey are able to stand much adverse weatlu'r. 
'I'lie trees genei'ally riaudi a height of from 
eiglit to ten feel, and after ten months lliey 
could be rooted Old. The yani.s vary x'ei'y much in 
size, ami weigh from four lo fifty ]Hmmls each. 
Ill good lands, the (luaidily of manioc jiroduced 
is very large, liid tlie a\'erage may be caleii- 
]iited at fifteen ]ioiimls jier tree. 
i 7b he C'liitiiuieil. ) 
EEFUSli MATTERS AS MANURES. 
norms, skin, hair, hooves and feathers are all 
of some value as manure. They are highly nitro- 
genous substances, — the amount of nitrogen 
present being the test of their value, — though 
they are very tardy in their action in the soil. 
Skin and hooves are not so refractory as the 
others mentioned ; while feathers are particularly 
slow in decomposing. Skin refuse from taniierie.s 
when fresh is very valuable, but it is found 
often mixed with ]iieces of tanned leather which 
decompose very slowly. When made into coin- 
jiosts, these substances decompose faster, and 
become much sooner available as i^lant food. 
Sulphuric acid is sometimes used for acting on 
them, and superheated steam is also employed ; 
the great disadvantage in this latter process being 
the loss of ammonia which occurs with the escap- 
ing steam. For use in slow-growing crops the 
above are by no means to be despised. Blood 
as a waste material from slaughter-houses, is a 
highly nitrogenous manure and decomposes com- 
paratively easily, while it is not easily lo.st by 
the soil. It is best applied after being dried and 
reduced to a powder, mi.xed with bone or other 
phosphatic manures. 
Ashes from burnt wood, especially young twigs, 
contain a large amount of potash. Animal char- 
coal — the refuse from sugar manufactories, — is 
an excellent .source of phosphoric acid, and should 
be iqjplied ground for the best results. It is 
sometimes used for making superphosphate by 
the action of sulphuric acid. Soot which ess.en- 
tially consists of firmly-divided carbon and mineral 
matter, is valued for the fair projiortion of am- 
monia wliich it also contains. Soot, besides sup- 
plying ammonia, absorbs gases and saline matter, 
wiiile, by darkening the soil, it raises its tem- 
peratiu’e. 
Gas lime — the refuse from gaswordcs— should 
not be used fresh, but must be exposed to the 
atmosphere for some time before applying. 
Gas liquor might with advantage be used for 
saturating .saw dust and coir dust to facilitate 
distribution. 
Many of the refuse substances mentioned above 
are u.sed by manufacturers for making up arti- 
ficial manures which are sold in the market 
under various names. The term guano has been 
used to designate many of these prepared manures. 
For instance, European guano, which is a very fair 
manure, is made up of blood, horn, urine, Ac. 
that have been acted ujion chemically, and con- 
verted into a powdery fertilizer. Frey Bentos 
guano owes its origin to Liebig’s Extract of iUeat 
Company, and is inanufactured from the meat 
refuse into a good manure. 
Fish guano, a nitrogeneous manure, much used 
in Scotland, is made out of the refuse from 
sardiije and other lish-tinniiig works in Norway. 
Native guano, which can be traced back to .siuvage 
])reci]utatiou is, however, not held in much e.sti- 
iiuition. It will thus be .seen that while a great 
deal of refus(> matter is allowed to go to waste 
with us, it is used to ad\'antage in other countries 
for making maiiiin's of a fairly soluble character, 
and convenient form for apiilication to the land. 
I'lie least that might be done by nalivi' agri- 
culturists, who think so little of making a return 
to I hi> soil they ciiltii ate, is to form comjio.sts of 
such refuse matters as are a\ailable in towns, 
