Oct, 1, 1900.] 
THE TROPICAL AGRICULTURIST. 
235 
SWEET CASSAVA. 
[Manihot utihssisma ) 
The follovviu^; results have been recently been 
obtained by Professor Carmody as the result of an 
E-Kamination of Sweet Cassava (Jamaica variety) 
grown at the Experiment Station St. Claii. 
S.iMPLE Sweet Cassava, grown at St, Clair. 
Prussic Acid .. .. .. .. O'l/ 
This is fully in accord with the result obtained 
by Francis, published in Analyst for 1877, in which, 
the mean of fifteen samples was found to be H. O.N, 
■01t')8 or 1-175 grains per lb. Dr. Taylor fixes the 
poisonous dose of Prussic acid at one grain, but at 
the same time reports the death of a healthy woman 
who died in twenty minutes from a dose equivalent 
to 9-10 of a grain of Anhydrous prussic acid. It 
appears therefore that the root is distinctly poisonous 
in its raw state, and that it is rendered harmless 
by cooking, for some of the roots were eaten by 
myself and four members of my family on the day 
it was dug up, without inconvenience. It would be 
convenient to know how much of the poison is in 
the skin of the root and how much among the 
starchy fibres; how much is dispersed by boiling 
or roasting, and how much is left in the substance 
when i-educed to an eatable state. In countries where 
Cassava is the staple article of food ; cases of poisoning 
by it are seldom heard of, but the poison found in 
the root by the Professor and the cases of reputed 
poisoning which have occurred, appear to show that 
a full examination of our product is necessary for 
the safety of consumers and we believe that work 
on these points is in hand under Profpssor Carmody's 
direction and will soon be forthcoming. Fowls eat 
the fresh roots without poisonous results following. — 
Trinidad Bulletin. 
TOBACCO AS AN INSECTICIDE. 
In answer to Mr. W. Lawlor of Sunnyside, Ten- 
terfield, who asks for advice as to the most effective 
way of using tobacco (ordinary dried leaf) for insect 
pests, the Entomologist, Mr. VV. W. Froggatt, says ; 
It can be used in the two following ways : — For 
aphis, the roots of the affected trees are bared, 
and the tobacco, ground to powder, is dusted well 
over the roots and ground about them. A ring 
of tobacco dust is put round the trunk of the tree 
just below the surface. The earth is then thrown 
back, and when rain comes the nicotine is washed 
out of the tobacco, and gets spread over the roots, 
killing all black or woolly aphides with which it 
comes in contact. 
Secondly, as a wash : 1 lb. of waste tobacco will 
make about for gallons of wash, and Jib. of soap 
is added to make it more adhesive, i'he leaf can 
be steeped in cold water over night, and the soap 
boiled up and added ; but most orchardists boil up 
the leaf and soap together, straining the resulting 
liquor and applying it hot. Tobacco is a contact 
poison, and is the best known remedy for soft-bodied 
things like aphides, but it does not affect scale in- 
sects very much, when they are full grown and pro- 
tected by their shelly outer covering. If tobacco wash 
could be sprayed on to the larvae of scale insect-s it 
would destroy them wholesale. — The Agricultural 
Gazette of New South Wales. 
^ 
TOBACCO CURING 
A year or so ago I ventured to recommend to 
onr Himalayan planters' attention the Sumatra va- 
riety of tobacco plant, on the grounds that it grew 
remarkably well in good soils in the hills, and had 
proved itself exceptionally hardy, producing durimg 
the monsoon season a very fine plant with beautifully 
fiue texture leaves. 0£ this there is not the slight- 
est doubt, provided the soil is good, the rainfall 
not too heavy, and the soil does not come water- 
logged. I find, however from correspondence and 
noi.es in various planting journals on this side, as 
distinguished from Madras, that the trouble is that 
of manufacture. This likewise I found ovit for myself, 
for although I had no difficulty in getting a fine 
plant, and none in hanging and ripening the leaf, 
yet when it came to the necessary fermenting a 
difficulty at once presented itself more especially as 
to the extent and degree of the ferment, 
I am strongly of opinion there are thousands of 
acres of admirable tobacco lands in the hills, and 
that the Himalayan regions should certainly during 
the monsoon produce a very superior tobacco, more 
especially as after the rains the weather is perfectly 
ideal for curing operations, collecting, and so forth. 
Some time ago I sav/ a writer put forth the as- 
sertion that Gauhauti could produce tobacco fully 
equal to that of Havannah. If there is anything in 
this assertion it is high time the planters of those 
parts woke up to the fact that tobacco of the quality 
produced in Havannah would fetch money and plenty 
of it to insure the business being highly profitable. 
This apart, however, increasing quantities of both 
Java and Sumatra tobacco are no doubt being bought 
for the covering leaf of Indian-made cigars, for, how- 
ever much the makers may puff Indian cigars, their 
first and chief recommendation, without Sumatra and 
Java covering leaf, is simply cheapness. 
The time was when the British public went to 
Chma for the sum total of its tea, but India has 
totally altered that state of things ; and why it should 
not produce all the tobacco it requires for its own 
consumption and some for export to boot is a thing 
I do not understand. Here is a country with a per- 
fectly marvellous range of climatic conditions and 
soils, and yet quantities of Java and Sumatra 
tobacco are imported, and American-grown tobacco is 
no doubt being increasingly imported into this country. 
Coming to the subject of curing, I have before me 
the latest revised edition of the Bulletins on the to- 
bacco industry in the United States, bearing date 1898, 
in which are set forth the methods practised in many 
parts of the United States by one of the chiefs of the 
United States Agricultural Department. 
It may be stated at once that of the fermenting pro- 
cesses " very little is known about the chemical chan- 
ges that occur in these processes." Again, there is a 
strong feeling among the more intelligent planters 
that more information is needed upon the changes 
which take place in order that these may be carefully 
controlled. After a careful perusal of the American 
publication I have no difficulty in forming the con- 
clusion that you can no more make a good tea-maker 
from book reading than you can a tobacco-curer. It 
has to be systematically learnt from observation. In- 
deed it is stated that even an expert cannot lay down 
written instructions that 'vill be certain to guide the 
operator aright. For the information, however, of 
planters, it may be stated that the farmers or planters 
of the States in a very large measure sell the tobacco 
uncured ; turning it over to the manufacturer for cur- 
ing. In this case the modus operandi is briefly as fol- 
lows : — The crop is planted in rows of 81 to 4 feet 
apart and 18 to 2-1 inches from plant to plant, it is top- 
ped from fifteen to eighteen leaves, and suckers taken 
off from time to time, that is, as I understand, in this 
case the side shoots and any emanating from the 
ground around the main plant. In cutting the plants 
a general average is struck, and the plants cut when 
the middle leaves are ripe. The plants at cutting 
time are laid on the ground to wilt for an hour or 
two, and turned if necessary to prevent scorching, 
and it is material the day of cutting be a fine dry 
one. A-fter wilting sufficient the plants are attached 
to laths and slung up in the withering barn, which 
is quite tight but provided with ventilators for venti- 
lation until the tobacco is thoroughly wilted. When 
thoroughly dried, which is at the outside in two 
mouths, it is taken down ; the leaves stripped fronj 
