256 
Agricultural Science. 
Vol. II. No. 10. 
(Jatroplia manihot or Aipi. ) 
SWEET CASSAVA 
BY H. V/. WILEY. 
About the middle of March, this year, I received from Mr. R. 
H. Burr of Bartow, Fla., a package of cassava roots. These roots 
reached the department in fine condition, being apparently as 
fresh as the day they were taken from the soil. After careful 
sampling and cleaning, a sufficient quantity of the roots was cut 
into thin slices and thoroughly dried. In a definite weighed por- 
tion, sampled as carefully as possible, the percentage of moisture 
was determined. The dried and powdered roots were preserved 
for future analysis. Owing to a press of other matter, this analy- 
sis was not made until the latter part of July, and the first of Au- 
gust this year. Mr. Burr, in forwarding the roots, sent the fol- 
lowing information concerning them : 
“ The roots do not last long after digging, drying up or rotting. 
Since this variety of cassava is not the bitter or poisonous kind, it 
is generally known in Florida as the sweet cassava. The roots 
are fed to all kinds of stock in a fresh state, and are greatly rel- 
ished. It has been sufficiently tested here to show its great value 
as a stock food. The yield under favorable conditions is astonish- 
ing. I have recently dug one plant of one year’s growth, which 
weighed 50 pounds, being at the rate of more than 1500 bushels 
to the acre. Eight hundred to 1000 bushels per acre can be con- 
fidently reckoned on.” Agricultural Science. 
257 
The roots received by us were long and slender, and of various 
sizes ; some of them were quite two feet long, and weighed sev- 
eral pounds. The bark, which contains the poisonous principle, 
if any be present, was carefully scraped off and has been preserved 
for subsequent examination. The analysis of the sample, calcu- 
lated to dry substance, is given in the following table: 
Serial No 
Oil (petroleum ether extract) 
Ether extract (glucosides, alcaloids, organic acids, etc.,).. 
Alcohol extract (amids, sugars, resius, etc.,) 
Crude fibre 
Starch 
Albuminoids (calculated from nitrogen) 
••• 5547 
74 
17 43 
.... 4.03 
... 71-85 
3-47 
100.73 
In regard to the method of analysis, little need be said ; it was 
carried on in accordance with the well-established rules of plant 
analysis, as laid down by Dragendorff. The first extraction of 
petroleum ether gave the fat or oil alone, and the subsequent ex- 
traction with sulphuric ether gave the glucosides, alcaloids and 
organic acids. That portion of nitrogen existing as amids has 
been estimated in the alcoholic extract. The total nitrogen was 
also estimated and entered as albuminoids ; a small portion of the 
nitrogen has thus been counted twice in the total results which 
add up a little over ioo. A characteristic feature of the cassava 
root is shown in the large amount of substance present, soluble in 
alcohol. The amount of starch also compares fairly well with the 
best varieties of potatoes. On account of the large quantity of 
sugars present, the cassava root could be more economically used 
for the manufacture of glucose than for starch ; there is no doubt, 
however, of the fact that a fine article of starch food can be made 
from the cassava root growing in this country. 
In addition to the fresh root above noted, two samples of the 
dried root, or cassava meal have also been examined. No. 5922 
was sent to us, described as pulverized manihot root or cassava 
flour. The root is first peeled, chopped into thin slices, dried in 
the sun two days and pulverized. It was prepared by Prof. W. 
H. Kern, of Bartow, Fla. No. 5923 was labeled, pulverized cas- 
sava, with the starch, or a portion of it, and glucose washed out, 
the remaining pulp dried in the sun, prepared by Prof. Kern. 
Prof. Kern sent a letter with the samples from which the fol- 
lowing extracts are made : 
“Allow me to say that owing to the prodigious yield per acre 
of what we here know as cassava, and its alleged value as a feed 
and food plant, and for its yield of starch and glucose, it is at- 
tracting a very great deal of attention here now. The plant here 
grown is different from the manioc root of South aud Central 
America ; our root contains no poisonous elements which need to 258 
be dissipated by heat. It is customary here for many persons 
to make their own starch from it. The root, which must remain 
in the ground until one is ready to use it, is dug, washed and its 
two inner and outer peelings removed ; it is then grated and the 
pulp washed, the water poured off in a vessel and allowed to 
stand when the pure starch settles in the bottom The clear 
water is again drawn off and the starch allowed to dry. The pulp, 
after having the starch washed out, may be used at once in mak- 
ing puddings by the addition of milk, eggs, etc. This washed 
pulp may be sun dried and thus kept, forming valuable meal or 
flour from which nice bread may be made. Necessitated as we 
are in south Florida to buy all our wheat flour, anything which 
acts as a substitute, either in whole or in part, is of great value 
to us.’’ 
The analyses of two samples of flour are given in the following 
Agricultural Science. 
Vol. II. No. 10. 
table : 
Serial No 
5922 
5923 
Water 
10.56 per cent. 
11.86 percent. 
Ash 
186 
1.13 
Oil and fat 
1-50 
.86 
Glucosides, alcaloids and organic acids. 
.64 
•43 
Arnids, sugars, resins 
13.69 
4-50 
Dextrine, gum, etc., by difference 
2.85 
5-63 
Crude fiber..’. 
2.96 <l 
4-15 
Nitrogenous bodies 
i-31 
1.31 
Starch 
64.63 
70.13 
From the above analyses it is seen that the cassava can never 
take the place of the flour made from cereals, as a food material, 
on account of the small portion of nitrogenous matter which it 
contains. It seems to me, however, that it might very well take 
the place of potatoes, and its value as a food should not be under- 
estimated. 
Mr. S. W. Carson, of Midland, Pda., has made some very val- 
uable contributions to the literature of the native cassava. From 
a letter of his to the Florida farmer and fruit grower of April 11, 
1888, I make the following quotations : 
“As before stated, I regard the rolling pine lands, containing 
some willow oak, to be the best for cassava, and the southern 
counties to be best suited to it. L,et the soil be well prepared 
by plowing and harrowing, rows checked about four feet apart, 
one piece laid in each hill. I think they should never be closer 
together than four feet, and five would be better. Cassava has 
been known to grow for three years in this country. It will 
continue to grow until the cold kills it, then by breaking off 
the stems when they are red, the stubble will sprout up in the 
spring. As to the seeds of the cassava they will ripen in about 
one year. If puddings, custards, etc., are desired, the roots must 
be peeled and grated ; salt, sugar, etc., may be used according 
to taste. The Spaniards make bread of it simply by grating Agricultural Science. 
259 
the root, and adding sait and a little soda. Now there is no 
doubt in my mind but that thirty tons of cassava root per acre 
can be produced. When I think of the tapioca, glucose and 
starch there are in it, and how abundantly it can be turned into 
bacon and lard, milk and butter, mutton and beef, I feel con- 
fident that it will pay better than any other plant in the world.” 
Mr. J. H. Moore, of Keuka, Fla., in a letter to the same paper 
of November 24, 1887, describes some of the uses of cassava. 
From his letter I make the following extract: 
“Cut the stalks about one inch above the ground, just before 
frost; after cutting, the stalks should be left to dry in a cool place a 
few weeks, and then placed in a trench and covered until time for 
planting. Some save the stalks by keeping them in a dry cool 
place until February and then plant. The roots should be dug 
as used; they will not keep in good condition out of the ground more 
than three or four days. It is perhaps the best feed we can raise 
for hogs ; it is also a fine feed for poultry. We often bake it like 
sweet potatoes, and also slice and fry it like Irish potatoes.” 
M. Sacc has addressed a letter to the national society of agricul- 
ture of France, concerning the cassava which he calls “ Manihot 
UtilissimaHe is of the opinion that the poisonous varieties 
are different botauically from the innocent. Manihot is the bread 
of tropical regions. The innocent variety is cultivated in Bolivia, 
and the botanists there call it “ manihot aipi.” The plant grows 
from one to two metres in height, with straight and naked stalks, 
since they only develop leaves at their extremities ; the only 
care given to them in their cultivation is to keep them free from 
weeds. The roots, to the number of five to nine, are of the size 
of the closed hand. The following analysis of the roots of the 
manihot ai’pi is given : 
Water 
Starch 
14 40 
Sugar, salts and malic acid 
Fibrin and yellow coloring matter 
08 
Crude fiber 
3-J6 
From the above it is seen that the roots of the tropical plant 
are quite different from those produced in our own country. In 
regard to the distribution of the two varieties, M. Sacc makes the 
following observation : 
“In Cuba I have seen only the poisonous variety. The same 
is true of Brazil, where I have not seen the manihot ai’pi except 
in the Swiss colony, Porto Real. As to the product of the two 
varieties, it is the same ; the stalks which are the size of the fin- 
ger, are from one to two metres in height. I have not been able 
to analyze the leaves ot this interesting vegetable, but as they 
are much sought after by cattle, they are probably very nutri- 
tious. ’ ’ 260 
Agricultural Science. 
Vol. II. No. 10. 
The above quotation from M. Sacc’s paper I have takenfrom the 
Revue agricole, (ii, 6, pp. 8r, 82.) published at Port Eouis Mau- 
rice. 
The name cassava should be applied properly only to the puri- 
fied starch derived from the roots of the plant. The plant is 
known under the botonical names, Janipha manihot.Manihot util- 
issimajatropha manihot,Manihot a'ipi&\\(\ Jatropha Laefflingii; it is 
also called the mandioc plant. The fleshy root of this plant yields 
the greatest portion of the daily food of the natives of tropical Amer- 
ica, and its starch is known in this country under the name of tapio- 
ca. Manihot is a woody or shrubby plant growing from fleshy tub- 
erous roots, the stems being smooth, and the leaves generally long- 
stalked. The leaves of the poisonous variety usually have seven 
branches palmately divided ; the leaves of the sweet variety are us- 
ually only five parted. In the “ Treasury of botany,” page 718, 
the following remarks are made concerning these two varieties: 
‘‘ It is quite clear that while the root of one is bitter, and a vir- 
ulent poison, that of the other is sweet and wholesome, and is com- 
monly eaten cooked as a vegetable. Both of them, especially the 
bitter, are most extensively cultivated over the greater part of 
tropical America, and yield an abundance of wholesome and nu- 
tritious food ; the poison of the bitter kind being got rid of dur- 
ing the process of preparation it undergoes. The poisonous ex- 
pressed juice, if allowed to settle, deposits a large quantity of 
starch known as Brazilian arrow-root or tapioca meal, from which 
the tapioca of the shops is prepared, by simply torrefying the 
moist starch upon hot plates, the heat causing the starch grains 
to swell and burst and become agglutinated together. A sauce 
called cassa?'eep used for flavoring soups and other dishes, partic- 
ularly the West Indian dish known as pepper-pot is also prepared 
from this juice by concentrating and rendering it harmless by 
boiling. Another of the products of cassava is an intoxiating 
beverage called piwarrie, but the manner of preparing it is not 
calculated to render it tempting to Europeans. It is made by the 
women who chew cassava cakes and throw the masticated mater- 
ials into a wooden bowl where it is allowed to ferment for some 
days, and then boiled. It is said to have an agreeable taste.” 
From the above analyses of cassava root, descriptions of its 
uses, and the amount of it that can be produced per acre, it is ev- 
ident that it is destined to become a valuable agricultural product 
of the sub-tropical portions of our country. 
U. S. department of agriculture. 
Washington, D. C., Sep. 5, 1888.