Feb 1, 1900.] THE TROPICAL 
AGRICULTURIST. 
553 
INDIGO: A THREATENED INDUSTRY. 
The kind of help wiiich the Government might 
well be asked to give to indigo growers, must here 
be made. The real merits of the dye produced 
from the plane must first be set forth and made 
known to the public, and the following extracts 
from a little pamphlet bearing the name of 
Fox Brothers and Co. (Limited) will suliiee to 
do all tliat is necessary ia this connexion. 
" The superiority of pure indigo over other dyes 
may be brietiy summed up as follows : — 
" I. F.istness of the dye. — Indigotin, the colour- 
ing principle of indigo, is insoluble in water, 
alcohol, ether, and dilute acids and alltalies, either 
hot or cold, hence its extreme fastness for all 
conditions of ordinary wear and tear. It is also 
fjuite fast to sunlight, and for an all-round dye 
there is nothing superior to it at present. There 
is no need to point out the advantage there is 
in a perfectly fast dj'e as compared with one 
which may be fast to light, but will not stand 
perspiration or washing, or vice w.rsa, 
" 2. Strength and handle. — Cloth dyed pure 
indigo is stronger and tougher than the same 
cloth dyed in other ways, owing to the dye-bath 
being at a comparatively low teniperature and the 
absence of any injurious chemicals or mordants. 
In almost all other dyes the cloth is first boiled 
in i;iordant and then in the dye, for some hours 
altogether; this always impoverishes the wool fibre 
and destroys much of its natural lustre and soft- 
ness, whereas the indigo vat with its soft mellow 
liquor adds to the fulness and richness of the 
fabric. Indigo dyeing being a mechanical process 
rather than a chemical one actually feeds 
the cloth. 
" Pure indigo tests — There are so many ways of 
producing a blue very similar to pure indigo that 
it is of the first importance to make quite sure 
that what is called ' pure indigo ' is pure indigo 
and nothing else. The following simple tests will 
give a fairly good indication whether the dye is a 
pure indigo or not. In carrying them out, the 
tests should always be compared with similar tests 
on a known pure dyea fabric of like quality : — 
"Nitric acid test. — Put two or three drops of 
ordinary commercial nitric acid on the same spot 
of the fabric. A yellow spot with a green lim 
quickly appears if the dye is pure indigo. 
"Sulphuric" acid and water. — Make a mixture 
(about half a pint) of sulphuric acid and water, 
and in it boil quickly for ten minutes a small 
piece of the cloth to be tested, say 1 l-2in. square. 
The acid and water must be in the proportion 
of one part acid to nine parts water, and care 
must he taken to always gently pour the acid 
into the water and not the water into the acid. 
If the cloth which has been boiled is pure indigo, 
the solution will remain colourless, 
" Soda and water. — Dissolve about 1 oz. of common 
Washing soda in half a pint of water, and gently boil 
in it for 15 miuutes a small piece of the cloth about 
11-2 in square. If the dye is pure indigo the liquid 
will remain colourless. 
" In conclusion. — Our motive for placing this, 
LITTLE SKETCH OF PURE INDIGO DSEINO, 
before the public is that from long experiences 
and countless experiments extending over 
many years we believe that there is nodye in 
the world equal to pure indigo, and our own 
experience is corrroborated by evidence from all parts 
of the world. The one important point we wish to 
impress upon the public is that when ordering ' pure 
indigo' they must be sure that they get it as an 
Unjnense amount of so called pure indigo is jmnnally 
placed on the market, and the term 'indigo' or, 
trade indigo is often applied to absolutely worthless 
dyes. To assist the public we have included the fore- 
going few simple tests, any two of which taken 
together, are sufficient proof as to the genuineness 
of the dye. 
Seeing that there ia no bine dye in the world equal 
to natural indigo, and that immense qaantities of 
substitutes are used and sold under nrore or less the 
same name, it appears to be necessary, iu the in- 
terests of (d\ the Government of India, (h) the plant- 
ers in that country, and (c) the public who wear 
clothing dyed with this material, to take measures 
to ensure that the real dye shall be used, or the 
fact that a substitute has been used made patent to 
everybody. The suggestion to be made then is that 
our Government with the concurrence of the Indian 
Govern.aent, should be asked to legislate, if the ob- 
ject iu view cannot be attained short of this, stating 
in effect that henceforward there shall be stamped 
upon each piece of blue cloth words guaranteeing that 
the dyeing material used in its jsroduction is natural 
indigo — or indigo from the plant grown in India — or, if 
with a substitute therefore that this fact and the 
name of the substitute shall be so stated upon such 
cloths. Further, no indigo substitute should be 
permitted to be imported into or sold in, this country 
bearing the name " indigo " or other similar name. 
This seems to be a reasonable request to make of the 
Government, and clauses could no doubt be drawn to 
secure the prime object in view. 
Some remarks have still to be made addressed to the 
indigo planters themselves. In the first place, as to 
the exchange questionj they must fully recognize the 
existing position, for they may rest assured the 
Government of India will not change its policy to 
please them. The report of the Fowler Committee 
and the action taken by the Government since make 
that perfectly evident. They should endeavour to get 
the Government to carry into effect the suggestion last 
above made, which from all points of view seems to be 
not only reasonable but necessary, for the reasona 
already set forth. 
It is known that the planters, under expert chemical 
advice, are experimenting to discover whether a (jreater 
quantity of dyeing material cannot be extracted from 
the plant, without detriment to the quality, than has 
heretofore, under the old system of manufacture, been 
possible ; but up till now it ia believed that no real 
success has attended these experiments. Whether 
they will be successful in the near future remains to 
be seen. The steps taken are certainly in the right 
direction. 
The next point has reference to production. There 
are good grounds for believing that the depressed 
state of the industry at the present time fortunately 
much less marked than it was only a few months ago, 
owing chiefly to the fact that the current year's crop 
from India is to be an exceedingly short one, has 
been brought about more by what may be called "over- 
production" than anything else. In any ease, over- 
production plus the discovery of " the new synthetic 
indigo," and the putting of it on the market for sale, 
which users of indigo have, of course, made the most 
ofi iu order to break down prices of the real article, 
have together brought about the depression. 
Very probably, 
OVEE- PEODUCTION, 
was due to a too large extension of cultivation, in com- 
bination, perhaps, with seasonable weather and con- 
sequent normal yield per acre. In growing indigo it 
must be kept in mind that a very large proportion 
of the season's outlay of money is incurred in pre- 
paring the lands for the reception of the seed, and 
that the preparation extend over months before a 
seed is put in the ground. Then the plant is perhaps 
the most troublesome to grow in India. Drought, too 
little rain, too much rain, rain at wrong times, all 
alike damage the crop, and little or nothing can be 
d ne by the planter in ellecting savings in his expendi- 
ture. It is accordingly of very great importance to 
t^je planter to secure a full yield per agre, but noli 
