Mauch 2, 1903.] Sttpplement to the " Trdpcdl AgricuUuris't.'" 
647 
THE VALUE OF MANIOC AS FOOD. 
In view uo doubt of the attention being given 
(in America as well as in India) to Manioc or 
Cassava as a food, a useful paper dealing with the 
nutritive value of the article as such appears in the 
January number of the Queensland Agricultural 
Journal, from which the information given below 
is gathered : — 
It is generally understood that there are two 
distinct varieties of manioc, viz., the sweet {Mani- 
Aof ai/>«) and the bitter (M. utilissima), but the 
difference is believed by many to be induced by 
the character of the soil. 
The so-c:illed sweet cassava is largely grown for 
human and cattle food, and the starch from it is 
the source of commercial tapioca. This starch, 
which is its chief constituent is found to the 
extent of from 60 to 70 per cent, the Nitrogen 
from 1 to \, aud proteids from 7^ to 3^ per cent, 
that is iu the dry materials ; the higher the per- 
centage of starch, the lower that of nitrogen and 
proteids; so that the richer the soil, the more 
uitrogeuous matter aud less starch. In comparison 
with wheat and even Indian corn, cassava is 
inferior owing to the low proportion of proteids. 
The most serious point, however, iu connection 
with the use of manioc as a food is the presence 
of Hydrocyanic or Prussic acid, which, though 
equally present iu all forms, is in the sweet 
cassava locUed chiefly iu the outer skin and riud. 
This poison, which makes the root dangerous for 
food iu the natural state, cau fortunately be 
completely eliminated by thorough boiling and 
after washing, and it is advised that this treatment 
should be carried out in the preparation of any 
form of human or cattle food made from it. 
According to Dr. Wiley, the well-known Ameri- 
can chemist, the amount of Hydrocyanic acid iu 
the roots is relative to the amount of nitrogen 
contained in them, and as this element varies 
according to the nature of the soil, the poorer the 
soil, the less nitrogen and less poison. 
It has been found b/ chemical examination that 
the dangerous element is ou an average found to 
the e.\tent of 2'01 grains per lb. iu the fresh, aud 
5'39 grains per lb. in the dry material, so that a 
horse would only need to consume 3 lbs. of the 
dry or 8 lbs. of il>e green root, aiuf a man 3 oz. of 
dry and 8 oz. of fresh material for a fatal dose. 
So that iu the natural state manioc must be 
cousisteutly avoided. 
BY HIGHWAYS AND HEDGES. 
it is not, I ihiuk, generally known that among 
uative plants we have two species of vanilla, 
viz., V. Walkericc and V. Moonii, I fancy it 
is the latter that I have seen between Daudu- 
gamuwa and Panuala iu the N. W. Province, 
near Kankaniyamullo, where a resourceful local 
resident has cured the beans after his own 
fashion for flavouring his favourite liquor I 
A notable specimen of Fithecolobium saman, 
the " rain tree," is the one in the Bilhul Oya 
Kesthouse compound, no doubt one of the first 
plants put down tvhen the tree v/as introduced 
into the Island. It is an enormous specimen, and 
is said to have been planted by some G. A. or 
A. G. A. of the olden time. 
In some villages, as iu the Kalutara district, 
one sees exposed for sale o.i the way-side fairly 
large-sized catkins of what is locjlly called 
wel-mal, Si''ibo, and Eatabulat-wel, bitanically 
known as Piper Siriboa (a variety P. Betle). 
These catkins are used for chewing with betel 
and its coucommitants, in order to impart a 
pungency to them, just as the root of Kaemp- 
feria yalanya (Sin. Hinguru-piyali), the flower 
buds of Alpinia nutans (Rankiriya), and the seeds 
of the cardamoUi are used. 
When cutting up the yam called ratala, a 
bright red dye may be seen just beneath the 
outer cuticle, imparting to the yam itself, on its 
outside sutface, a purplish tinge somewhat 
like that of the well-kuown " Jaffna yam." This 
dye is readily extracted by metyllated spirits, 
and on evaporation leaves a sediment. So that 
it is possible to use the dye for colouring 
food in place of cochineal, which I have known 
people object to, owing to its animal origin. 
Memecylon umbellutum, called in Sinhalese 
korakaha, is well known as a source of a yellow 
dye got from its leaves, but I was not aware 
till lately that the beautiful bosses of bright blue 
flowers which make this tree so conspicuous an 
object amid forest flora, are made to yield a blue 
colouring matter used in Sinhalese painting*. 
.\ very handsome tree is mas-moTa {Adenanthera 
bicolor) next door neighbour to the well-known 
and commou madatiya with its briglit red seeds, 
a favourite plaything with children from its 
resemblance to red coral, and used also by gold 
aud silversmith-; as weiglits of about 4 grains 
each. (Haasted madatiya sometimes h.nvked 
about for sale is a thing to be avoided owing to 
its extreme indigestibility). The young foliage 
of mas-mora, which is coloured pink, is a pretty 
elemeut iu forest vegetation. The tree is com- 
mou near Matugama. 
In the neighbourhood of Pelmadulla and Rak- 
waua are to be fouud some of tlie largest .-peci- 
mens of the Eatada Scandens (puswel) wiLli its 
huge polished leathery seeds b rought dowu by 
streams (along which the climber is generally found) 
into the sea aud cast up ou the beach, where it is 
picked up aud used as a toy. This seed (called 
" Bataug " in Sinhalese) is a good instance of 
seeds designed by nature to retain their vitality, 
in spite of long immersion while being trausported 
through the agency of water. I have a specimen 
of the bean 50 in. long gathered near AVelandura. 
The leaves of a plaut of the Caper family 
known as W'dla (Gynandropsis ventaphylla) 
emit a strong and by no means pleasant odour. 
