The Sun.
London, England, 1845-10-30 00:00:00

THE POTATO, ITS HISTORY AND
CHEMICAL COMPOSITION.
MANUFACTURE OF POTATO STARCH.
(From the Northern Whig.)
As, at the present time, anything connected with the
potato excites general attention, it may be interesting to
bring before the public some notices of its history. A native
of the mountainous parts of Chili and Peru, in South
America, and, also, according to some late authorities, of the
Pic de Orizaba, in the Mexican territory, this now so valuable
plant appears to have been first brought to Europe by the
Spaniards, from the mountains near the city of Quito, about
the beginning of the 16th century. From 'Spain, it has been
traced to Italy, where it was cultivated as food both for man
and animals. Into Germany, we learn from the botanist M-
idas, the first writer in whose works any mention of it ap-
pears, that it was introduced by a person connected with the
suite of the Papal Ambassador at Vienna about the year
1598 ; and that, in a short time after that, it was exten-
sively diffused through the Germanic empire. Thus it i
seems that Ireland, though at the present time the chief
nursery of the potato, was not the first to receive it ; but, in
1584, the adventurous Raleigh, returning from his voyage to
Virginia, brought with him some seeds of the plant, and
placed them in his garden, at Youghal, in the county of
Cork. It is related that the seeds flourished, and that Sir
Walter, having sent for some of the produce, his gardener
brought to him the small apples produced upon the stem,
upon which lie imagined that the seeds which he had brought
home were not those of the plant which he had seen growing
in America, and directed the man to root it up ; but when
he proceeded to tear it away, some of the tubers came up
with the roots, and Sir Walter at once recognised the valua-
ble fruit which he had eaten in his travels. Gerard, the old
English herbalist, whose quaint history of plants appeared
in 1597, gives a description of potatoes, a specimen of which
he bad received from America, under the name of Virginia
Potatoes—a name which they had received to distinguish
them from the sweet potatoes, the prcduce of an entirely
different plant, which had been, long before that time, ex-
tensively used in England. These sweet potatoes are
alluded to by Shakspeare, when, in The Merry Wires of
Windsor, he makes his valiant Sir Jojm exclaim, " Let the
sky rain potatoes." Old Gerard recommends the potato as a
delicate dish, but net as an article 'of food, for common
use. "It is, he says, "an excellent thing for making sweet
sauces, and also to be eaten with sops and wine." Indeed, their
price in the reign of the first James wan so high—two shil-
lings the pound—that they could be introduced only at the
tables of the rich. The first extensive supply which Eng-
land received was from an Irish vessel, wrecked with a cargo,
on a part of the coast of Lancashire, called North Meols,
about 1605 ; but for many years their cultivation was con-
fined to the gardens in the neighbourh ood of London. In
1663, the attention of the members of the Royal Society of
London was directed to the importances of cultivating the
plant extensively over the kingdom, for the prevention of
famine ; but, notwithstanding their recommendation, very
few persons were induced to grow it; and even some writers,
of a later date, as Evelyn, in 1689, seemed to have been pre-
judiced against it. In fact, we do not find its value ap-
preciated before 1790, in which year it appears, for the
first time, to have been cultivated, to any extent, in the
open fields. It is remarked that Scotland, which, at pre-
sent, takes the lead in agricultural improvement, should be
among the last of the European Kingdoms to avail itself of
this important vegetable—its introduction into that country
being delayed until 1739 ; and, even then, religious, or,
rather, an irreligious bigotry, opposed itself to its use as an
article of food, and stirred up the people to reject it with
abhorrence, because it was not mentioned in the Bible !
In France, its use, as an article of diet, was, also, but for
different reasons, strongly opposed, and its cultivation con-
demned by many who considered themselves men of judg-
ment ; but, through the zealous efforts of a chemist—M.
Parmentier—who had the sagacity to perceive its value, it
was finally established in public estimation. One of the expe-
dients adopted by Parmentier to overcome the prejudices
of those who obstinately opposed its use, is interesting and
instructive, and might, occasionally, be advantageously
copied in our own times, as it is a good example of the pro-
per way of treating those who differ from us. He invited all
who scoffed at, and all who opposed, the potato cultivation
to a sumptuous dinner, at which he gave them nothing either
to eat or drink but what had been prepared from the potato.
We have, as might be expected, had a great many inves-
tigations of the chemical composition of the potato. M.
Parmentier, to whose enthusiastic advocacy of its value, in
France, I have above alluded, published an elaborate trea-
ties on its culture and chemical properties, in 1776 ; and,. a
great many years ago, Dr. Pearson presented the English
Board of Agriculture with an essay on the same subject.
The leading constituents of the potato tuber are the same
which we find in the grain of wheat—viz., water, starch,
starchy fibre, gum sugar, albumen, and salts. The follow-
ing analysis of Michael's, published in 1837, will give an
exact idea of its per-centage composition :
Starch and starchy fibrin
Albumen .503
Gluten .055.
Fat
Gum
Asparagin
Extractive
Citrates, silicates, and phosphates of potash,
soda, lime, magnesia, alumina, and pro-
toxide of iron and maganese
Chloride of potassium
Free citric acid
Water

.815
.176
.047
66.875

100.000
It would occupy too much space to enter, at greater length,
into the chemical history of the potato. I may, however,
remark, that it belongs to the same family of plants of which
the deadly nightshade is a member, and that it has been
discovered to contain a small quantity of the same poisonous
principle which exists in that plant, termed solanin. The
principle is, however, fortunately, removed in cooking. I
had resolved, in the present paper, to consider the value
which science shews us should be attached to the chief con-
stituent of the potato tuber—its starch in the nutrition of
the body;, but I have, within these few days, received so
many communications from parties anxious to obtain infor-
mation respecting the manufacture of that article, as a means
of enabling them to convert their crop into a form which
will resist decomposition, that it will be more advantageous
to give a description of the simple apparatus required for that
purpose.
The potato tuber, when examined by the aid of the micro.•
scope, is found to consist of small cells, in which the sub-
stance, which we term starch, is contained. This substance
does not, however, appear equally distributed over every
part of the tuber; when we examine a slice of the potato,
the starch is found in greatest quantity near its exterior,
while the centre contains so little of it, that it is almost
transparent. When a potato is grated upon any kind of
grater, its cells are torn in pieces, and the little grains of
starch which they contain liberated. These grains are ex-
ceedingly small—indeed, not larger than the two hundred
and fiftieth part of an inch in diameter; so that, if we place
the pulpy mass, consisting of the broken cells and the libe-
rated starch, upon a hair sieve, placed over a pan, and water
it from a watering-pot, so long as the water which runs
through has a milky colour, we, will find that all the starch
will be washed through the sieve, and that it will be deposited,
in the form of a fine white powder, at the bottom of the pan.
It is truly a most fortunate circumstance for the potato
cultivator, that microscopic examination shows the starch
contained in potatoes affected with the prevailing disease
to be perfectly uninjured, even when the tissue of which the
cells are formed was quite brown, and its smell most dis-
agreeable. I would, therefore, earnestly advise our farmers,
at once, to convert their diseased crop into farina; or, in
cases Wile' e the disease has only commenced, into the more
nutritious and easily-prepared potato meal, as practised on
the Continent.
The process, which I have described above, represents the
preparation of starch in its most simple form; but it is
obvious that; in the present circumstances of the potato crop,
in this country, the farmer must have recourse to a less
troublesome and more expeditious method. The manufac-
ture on the large scale, however, presents no difficulty, the
esential operations in the process for preparing a on of
starch being precisely the same as those employed in making
a few ounces with the cottage grater; the main requisites to
the perfection of the work being extreme attention to clean-
liness, in all its parts, and an abundant supply of pore water.
Vie operations required in the manufacture may be conve-
niently considered under five heads :
Ist. The washing of the potatoes.
2d. The grinding, or rasping of the potatoes.
3d. The wailing of the starch from the pulp.
4th. The washing and purification of the starch.
sth. The drying.
I. Suppose a farmer wishes to convert the half-rotten
portion of his crop into starch, he must, in the first place,
carefully wash the potatoes, so as to remove all adherent
soil, &c., in the common potato-washer of the farm, or in any
convenient way. In large manufacturing establishments they
are placed in a cylindrical cage or wooden puncheon, bored
with hole., which is made to revolve in a trough filled with
water, and into which a current of water flows, from a cis-
tern or mill stream. When thoroughly washed, the potatoes
are to be removed to the rasping machine.

2. The object of rasping or grin ing the potato is, as I
have already explained, to break up its cells, so as to libe-
rate their contained starch. It will, therefore, be obvious,
that the more effectually this be accomplished—the more
perfectly the fibre be reduced to a fine pulp—the greater
will be the quantity of starch produced. The rasping ma-
chine usually employed, and which will be most conveniently
prepared for the purposes of the farmer, consists of a
wooden cylinder or drum, about 2 feet long and 1 feet in
diameter, covered on its circumference with sheet iron,
converted into a rasp, by being punched with holes from the
opposite side. The potatoes are supplied from a hopper, like
that of a common mill, placed above the rasp, and with its
bottom nearly in contact with it. In Germany, in the small
mantuacteries, a machine is employed both for rasping pc -
tatoes for starch and beet, for the preparation of sugar, nearly
similar to that just described, but constructed of cast iron,
and armed with saw teeth. During the rasping, to prevent
clogging, a small stream of water, from a cistern, is made to
drop from a tube, perforated with holes, placed over the
drum. The rasping machine may easily be worked by a
horse; but it. will be more advantageous, when local circum-
stances render it possible, to connect both the washing and
rasping machines with a water-wheel.
3. Under th&rasping machine must be placed a convenient
wooden tub or vat, covered with a fine hair or wire-web
sieve, and so arranged, that a pipe, conveying water from the
cistern, may discharge itself over it. Upon this sieve, the
pulp, consisting of the cellular tissue of the broken-up
potatoes, is caught ; while the fine grains, liberated from
these cells, are washed through by the current of water, and
deposited at the bottom of the tub. When this tub is full,
it is either removed, and another substituted, or the starch is
stirred up with the water, and run off, by means of a trough,
into large wooden vessels, where it is washed and purified.
4. In the, purifying vats, the particles of starch gradually
deposit themselves from the water ; and, if this deposit be
examined, it will be found to consist of two layers, that at the
bottom of the vessel being composed of white shining grains
of pure starch ; while, on the top, we will have the starch
rendered impure and dirty-looking, from containing bits of
fibre not removed by the sieve, flakes. of albuminous matter,
&c. In the water, covering the starch, will be found all the
soluble ingredient of the potato. To remove these impurities,
it will be necessary, in the first place, by means of a plug-
hole in the vat, to draw off the discoloured water ; after
which, the vat should be again filled with pure water, the
starch stirred up through it, and the milky liquid, if a par-
ticularly nice article be required, passed again through the
sieve. This additional operation is, however, but seldom ae-
cessarY ; as, by mixing the starch with clean water, two or
three times, and drawing the water off, if impure, the starch
'will, in general, be deposited of a good colour. It has been
suggested to 'wash the starch with water containing a little
chlorine, but we cannot expect our farmers to to this
direction ; indeed, it is only required by the
manufac-
turer, who wishes to send his starch into the large
market as a
:substitute for "fine Jamaica arrowroot."
5. Having prepared the starch, as I have described, the
next matter for us to consider is, the best method of drying
it. On this subject I have received. several communications.
from farmers, who imagined that. it would be impossible, in a
farm establishment, to contrive any proper arrangement for
qubantity prepared is not very great,
this purpose. When the
it may, without difficulty, e rendered sufficiently dry, by
placing it in shallow wooden trays, supported on shelves in a
'TOM heated by a stove ; but, when the manufacture is con-
flucted on a larger scale, it will be the interest of the farmer