N E R I U Me 731 
filled with cold water, to within two Or three inches of the 
top ; and fo much muft be left, becaufe here the bulk en¬ 
larges by the heat, fully as much as the common indigo- 
vat does by fermentation. The fire is then lighted, which 
muft be maintained rather brilkly till the liquor acquires 
a deep green colour when viewed in the velfel; but, if 
taken up,and poured from one veffel into another, it will 
appear of a pale but bright greenifli colour: the leaves will 
then begin to afi'ume a yellowifh colour, and the heat 
of the liquor will be of about 150 or 160 degrees of Fah¬ 
renheit’s feale. Little dependence can be placed on the 
copper or violet leum, as the leaves muft be conftantly 
agitated, and turned upfide down, to produce, as nearly 
as poffible, an equal degree of fealding: if not, thofe at 
the bottom would be much overdone before thofe at 
the furface were ready. The motion anfwers another 
purpofe, it ferves to expel the fixed air, which greatly for¬ 
wards the operation. The fires muff be withdrawn, or 
•fullered to die away, fome little time before the liquor 
has acquired the above-mentioned appearance; and it is 
meceflary to have all the different veffels, that are to be 
let into the fame agitation-vat, ready at the fame time : a 
little praflice will foon render this eafy of performance. 
When they are ready, the whole is drawn off at once. A 
contrivance muft be made to let the liquor pafs through 
a hair-cloth, (a coarfe eonily, fuch as the poorer claffes of 
the natives wear in cold weather, anfwers remarkably 
well,) to prevent any of the leaves, See. getting into the 
agitation-vat with it. As foon as the w'hole is run off, it 
muft be, while hot, agitated in the common way for a few 
minutes ; from five to twenty will generally be found 
fufficient to produce the neceffary degree of granulation. 
About from one-feventieth to one-hundredth part of 
ftrong pure lime-water is then let in (the liquor being ftill 
hot) from the lime-water ciftern, which requires only to 
be fufficiently mixed with the liquor, to produce, quickly, 
a very large grain, which foon precipitates. The fuper- 
natant liquor is then let off, and the reft of the procefs is 
exadlly as in making the common fermented indigo. If 
the procefs has been properly .conducted, the fupernatant 
liquor will run off of a clear Madeira-wine colour, which 
is a fign that it retains none of the indigo ; and the pro¬ 
duce of indigo, when dry, will average about one pound, 
from every two hundred and fifty pounds of the green 
leaves 5 but varies according to the feafon and ftate of the 
weather when gathered.” 
The quick and luxuriant growth of this tree, in its na¬ 
tive foil, will be a great inducement to thofe who wifli to 
cultivate it, which can require little or no trouble ; and 
the foil that it is always found wild in is the barren dry 
rocky hills, and lower region of mountains, which is to¬ 
tally unfit for every fort of agriculture. The lower parts 
of the fteep rocky mountains of St. Helena feem to be 
the very foil and fituation it delights in ; its fizeand quick 
growth will render it valuable there, if it be only for fire¬ 
wood ; with that view Dr. Roxburgh fent a pretty large 
quantity of feeds to the Planter’s Society on that ifland. 
It may be faid that we are already in poffeffion of a fuffi- 
cient number of good blues, confequently that it is unne- 
ceffary to attend to this new indigo. To obviate this ob¬ 
jection,it may be obferved, that the common indigo-plant 
is only to be brought to perfection by nice, expeniive, and 
labouring, culture ; is liable to many accidents, from 
changes ofw'eather, and other caufes that no human fore¬ 
fight can prevent: thefe are well-known faCts to every 
one that cultivates indigo to any extent. This tree is 
not fubjeCt to thefe inconveniences ; betides, it requires 
not the fmalleft care, is found in the greateft abundance, 
growing wild in the moft barren traCls that can poffibly be 
imagined, and requires only to be cut down once every 
year, to make it produce a large fupply of young thoots, 
with very luxuriant leaves, the following feafon ; befides, 
the colour that this indigo may give to cloth, &c. may be 
different from any other hitherto known; confequently, 
may prove of confiderable benefit to a commercial nation 
J.ihe Great Britain. 
In the annexed Engraving, fig. t. reprefents a final! 
branch of the nerium-plant in flower. Fig. 2. is a view 
of the nerium indigo-works, as praftifed at Hindooftan; 
of which the following figures afford an analyfis and ex¬ 
planation. 
Fig. 3 is the plan, taken at the grate, or iron bars 
which fupport the coppers over the fire. The letters are. 
the fame as are explained under fig. 5. 
Fig. 4. a longitudinal fcCtion expofes to view the ftruc- 
ture of the works. A, a ciftern for holding w'ater in rea-, 
dinefs to fill the coppers. It is fifteen feet fquare, and 
three deep, a, the channel for conducting the water 
from the ciftern into the coppers, which is about two 
inches above the bottom, that any impurities may fettle 
at the bottom ; b, a channel for the impurities to be 
drawn oft’ at, and for the ciftern to be cleaned. To raile 
the water to fill this ciftern, is an objedl of much confe- 
quence : in feveral places among!! the hills, where the 
Nerium grows, there are little rills of water, running upon 
fuch a defeent, as to render it only neceflary to conftruct 
the works on fome low adjacent fpot, that the water may 
be conducted, with little trouble, into the ciftern. When 
no fuch fupply of water can be had, pecota/ts, or a chain- 
pump made of four boards, (as defcribed and figured in 
the Encyclopaedia Britannica, article Pump,) may be 
ufed ; or, if the water is very low, it may be done with the 
funnel-like leather bucket, which is wrought by a pair 
of buffaloes, or bullocks, backing to lower the bucket, &c. 
To the mouth of the tube or pipe of this leather funnel- 
bucket, fee X, fig. 2. is faftened a cord a, which leads over 
a roller at leaf! the length of the body of the bucket belo w 
the wheel V, over which the rope y that raifes it paffes; 
and immediately above the trough S, by which the water 
is conduced to the ciftern. The cord w, is of a length 
fufficient to keep the mouth of the pipe rather above the 
fquare mouth of the bucket, until it reaches the roller, 
which it paffes over, leading it into the trough, while the 
bucket continues to afeend, till its bottom is about the 
level with the trough ; by which time the whole of the 
water will have made its efcape within the trough. This 
method of railing a large quantity of water from a great 
depth, is in common ufe over many parts of Hindooftan, 
where the wells are too deep for the peentah, or lever. It 
is of great advantage to have the water in readinefs in this 
manner; for it not only forwards the work much, but alfo 
gives time for any impurities to fettle at the bottom. In 
the perfpeftive view, the ciftern A is omitted, to (how the 
other parts of the works on a larger feale. B, B, B, B, B, B, 
are the coppers, or fcalding-veffels. Here they are cut 
tranfverfely, reftingonthe grate c, which is fupported by 
the walls, and by the pillars dddddd; they are made 
to communicate with each other at the openings eeeeec; 
/’(hows the top of the walls which furround the velfels; 
it is two or three inches lower than the edges of the cop¬ 
pers, to prevent duff, &c. getting in, and fufficiently 
broad for the workmen to walk about on, to attend the 
work; n, n, n, n, n, n, the fire-places. C, the agitation- 
vat, or beater, twenty feet fquare, and three deep ; one 
foot of which, g, may be called the border, being thinner, 
and prevents dull and dirt getting in from the feet of the 
workmen, while walking about to agitate the liquor, &c. 
h, two feuppers for letting off the clear fupernatant liquor 
from the fecula; i, another to draw off the fecula by. D, 
the lime-water ciftern, which may be made with a border 
and lid to exclude the air, or arched, having an opening to 
put the lime and water in at, and fora boy to go in to clean it. 
The clofer this can belhut, the better will the lime-water 
be; k, the feupper for letting the lime-water into the 
agitation-vat. E, the fmall fecula-ciftern for the fecula 
to further fettle in ; l , feuppers to let off' the fupernatant 
liquor, and over them the bags are hung till the liquor 
drops clear from them. Note, in this fedtion the fecula 
and lime-water cifterns feem one over the other, but by 
the plan, fig. 2, their real places are feen. 
Fig. 5. a tranlverfe feftion, upon a larger feale than the 
former. It is through the middle of one of the coppers 
Fi 
