The temperature required to produce the desired result is not very clearly made out. Mr. Bollman's room, in which his first potatoes were dried, was heated to about 72 degrees, and much higher. By way of experiment he placed others in the chamber of the stove itself, where the thermometer stood at 136 degrees, and more. He also ascertained that the vitality of the potato is not affected, even if the rind is charred. Those who have the use of a malt-kiln, or even a lime-kiln, might try the effect of excessive drying, for a month seems to be long enough for the process.--(Gardener's Chronicle.)

A Mr. Penoyer, of Western Saratoga, Illinois, publishes the following, which he recommends as a perfect cure and preventive of the potato rot, having tested it thoroughly four years with perfect success; while others in the same field, who did not use the preventive, lost their entire crop by the rot. It not only prevents the rot, but restores the potato to its primitive vigor, and the product is not only sound, but double the size, consequently producing twice the quant.i.ty on the same ground, and the vines grow much larger, and retain their freshness and vitality until the frost kills them. Aside from the cure of the rot, the farmers would be more than doubly compensated for their trouble and expense in the increase and quality of the crop. The remedy or preventive is as follows:--"Take one peck of fine salt and mix it thoroughly with half a bushel of Nova Scotia plaster or gypsum (the plaster is the best), and immediately after hoeing the potatoes the second time, or just as the young potato begins to set, sprinkle on the main vines, next to the ground, a tablespoon full of the above mixture to each hill, and be sure to get it on the main vines, as it is found that the rot proceeds from a sting of an insect in the vine, and the mixture coming in contact with the vine, kills the effect of it before it reaches the potato." I cannot but consider Professor Bollman's as the most important of the two remedies suggested.

The potato crop of the United States exceeds 100 million bushels, nearly all of which are consumed in the country; the average exports of the last eight years not having exceeded 160,000 bushels per annum.

According to the census returns of 1840, the quant.i.ty of potatoes of all sorts raised in the Union, was 108,298,060 bushels; of 1850, 104,055,989 bushels, of which 38,259,196 bushels were sweet potatoes.

Last year (1852) there was under cultivation with potatoes in Canada, the following extent of land:--

Acres. Bushels.

Upper Canada 77,672 Produce 498,747 Lower Canada 73,244 Produce 456,111

About 782,008 cwts. of potatoes are annually exported from the Canary Islands. In Prussia, 153 million hectolitres of potatoes were raised in 1849. In 1840 Van Diemen's Land produced 15,000 tons of potatoes, on about 5,000 acres of land.

The potato is not yet an article of so much importance in France, as in England or the Low Countries, but within the last twenty years its cultivation has increased very rapidly. It is mostly grown where corn is the least cultivated. The quant.i.ty raised in 1818, was 29,231,867 hectolitres, which had increased in 1835 to 71,982,814 hectolitres.

About 2,000,000 hectolitres of chesnuts are also annually consumed in France, a portion of the rural population in some of the Central and Southern Departments living almost entirely on them for half the year.

In Peru dried potatoes are thus prepared:--Small potatoes are boiled, peeled, and then dried in the sun, but the best are those dried by the severe frosts on the mountains. In the Cordilleras they are covered with ice, until they a.s.sume a h.o.r.n.y appearance. Powdered, it is called _chimo_. They will keep for any length of time, and when used required to be bruised and soaked. If introduced as a vegetable substance in long sea voyages, the potato thus dried would be found wholesome and nourishing. A large and profitable business is now carried on, in what is called "preserved potatoes," for ships' use, prepared by Messrs.

Edwards and Co., which are found exceedingly useful in the Royal Navy, in emigrant ships, for troops and other services, from their portability, nutritious properties, and being uninjured by climate.

Few persons are probably aware of the quant.i.ty of potatoes used in England, America and the Continent, in the manufacture of starch, arrowroot, and tapioca, &c., A starch manufactory in Mercer, Maine, United States, grinds from 16,000 to 24,000 bushels annually of potatoes, and makes 140,000 to 240,000 lbs. of starch, which finds a ready market at Boston, at four dollars the hundred pounds. The New England manufacturers prefer it to Poland starch. Another starch manufacturer, in Hampden, America, consumes 2,500 bushels per day. In a single district in Bavaria, in Germany, 400,000 lbs. of sago and starch are manufactured from potatoes; 100 lbs. of potatoes are said to yield 12 lbs. of starch. From experiments made in America, with three varieties of potatoes, the long reds, Philadelphia, and pink-eyes, it was found that the former yielded the most starch, viz., about 6 lbs. to the bushel. A bushel of potatoes weighs about 64 lbs.

The following table from Acc.u.m, gives the rate of starch and component parts per cent. in different varieties:--

+-------------------+--------+-------+---------+------+---------+------+ | Sort. |Fibrine.|Starch.|Vegetable| Gum. |Acids and|Water.| | | | | Alb.u.men.| | Salts. | | +-------------------+--------+-------+---------+------+---------+------- |Red potatoes | 7.0 | 15.0 | 1.4 | 4.1 | 5.1 | 75.0 | |Ditto germinated | 6.8 | 12.2 | 1.3 | 3.7 | | 73.0 | |Potato sprouts | 2.8 | 0.4 | 0.4 | 3.3 | | 93.0 | |Kidney potatoes | 8.8 | 9.1 | 0.8 | | | 81.3 | |Large red ditto | 6.0 | 12.9 | 0.7 | | | 78.0 | |Sweet ditto | 8.2 | 15.1 | 0.8 | | 74.3 | |Potato of Peru | 5.2 | 15.0 | 1.9 | 1.9 | 76.0 | |Ditto of England | 6.8 | 12.9 | 1.1 | 1.7 | 77.5 | |Onion potato | 8.4 | 18.7 | 0.9 | 1.7 | 70.3 | |Voigtland | 7.1 | 15.4 | 1.2 | 2.0 | 74.3 | |Cultivated in the | | | | | | | environs of Paris| 6.8 | 13.3 | 0.9 | 3.3 | 1.4 | 73.1 | +-------------------+--------+-------+---------+------+---------+------+

The first six varieties were a.n.a.lysed by Einhoff, the next four by Lamped, and the last named by Henry.

YAMS.

The different species of yams have a wide range. In the West Indies there are several varieties, having distinctive names, according to quality, color, &c., as the white yam, the red yam, the negro yam, the creole yam, the afoo yam, the buck yam (_Dioscorea triphylla_), which is found wild in Java and the East; the Guinea yam, the Portuguese yam, the water yam, and the Indian yam, &c. The last is considered the most farinaceous and delicate in its texture, resembling in size the potato; most of the other sorts are coa.r.s.e, but still very nutritive and useful. The common yam (_Dioscorea sativa_) is indigenous to the Eastern Islands and West Indies. The Guinea yam (_D. aculeata_) is a native of the East. The Barbados or winged yam (_D. alata_?) has a widely extended range, being common to India, Java, Brazil, and Western Africa. The yam species are climbing plants, with handsome foliage, of the simplest culture, which succeed well in any light, rich, or sandy soil, and are readily increased by dividing the tuberous roots. The Indian, Barbados, and red yams are planted in the West Indies early in May, and dug early in the January following. If not bruised, they will keep well packed in ashes, the first nine, and the second and last twelvemonths. The Portuguese and Guinea yams are planted early in January and dug in September. Creole yams and Tanias are dug in January. Sweet potatoes from January to March. In most of our colonies large crops of the finest descriptions of yams, cocos, &c., could be obtained, but the planting of ground provisions is too much neglected by all cla.s.ses. From the tubers of yams of all sorts, and particularly the buck yam, starch is easily prepared, and of excellent quality. Some varieties of the buck yam are purple-fleshed, often of a very deep tint, approaching to black, and although this is an objection, because it renders more washing necessary, yet even from these the starch is at last obtained perfectly white.

As an edible root the buck yam, especially when grown in a light soil, is equal to the potato, if not superior to it. It does not, however, keep for any length of time, and therefore could not be exported to Europe, unless the roots were sliced and dried.

Yams and sweet potatoes thrive well in the northern parts of Australia; indeed the former are indigenous there, and const.i.tute the chief article of vegetable food used by the natives. The yam was introduced into Sweden, where it succeeded well, and bread, starch, and brandy were made from it, but it prefers a warmer climate.

Yams are occasionally brought to this country. When cooked, either by roasting or boiling, the root is even more nutritious than the potato, nor is it possessed of any unpalatable flavor, the pecularity being between that of rice and the potato. Dressed in milk, or mashed, they are absolutely a delicacy; and from the abundance in which they are cultivated in the West Indies and other parts, they promise to become a most economical and nutritious subst.i.tute for the potato.

The yam frequently grows to the enormous size of forty or fifty pounds weight, but in this large state it is coa.r.s.e-flavored and fibrous.

An acre of land is capable of producing 4 tons of yams, and the same quant.i.ty of sweet potatoes, within the twelve months, or nine tons per acre for both, being nearly as much as the return obtained at home in the cultivation of potatoes; and I have the authority of all a.n.a.lytical chemists for saying that in point of value, as an article of food, the superiority is as two to one in favor of the tropical roots.

The kidney-rooted yam (_D. pentaphylla_), is indigenous to the Polynesian islands, and is sometimes cultivated for its roots. It is called _kawaii_ in the Feejee islands. _D. bulbifera_, a native of the East, is also abundantly naturalised in the Polynesian islands, but is not considered edible.

There are seven or eight kinds of yams grown in India. Two are of a remarkably fine flavor, one weighing as much as eighteen pounds, the other three pounds. These are found in the Tartar country.

COCOS OR EDDOES

_Arum esculentum_.--This root has not hitherto been considered of sufficient importance to demand particular care in its cultivation, except by those who are engaged in agricultural pursuits, and derive their subsistence from the production of the soil. But though the cultivation of the root is almost unknown to the higher cla.s.ses in society, and little regarded by planters in the colonies, it is a most valuable article of consumption. Amongst the laboring population it is the princ.i.p.al dependence for a supply of food. Long droughts may disappoint the hopes of the yam crop, storms and blight may destroy the plantain walks, but neither dry or wet weather materially injure the coco; it will always make some return, and though it may not afford a plentiful crop, it will yield a sufficiency until a supply can be had from other sources. For this reason the laborer in the West Indies always takes care to put in a good plant of cocos to his provision ground as a stand by, and knowing their value, is perhaps the only person who bestows any degree of care or attention upon them.

Previous to their emanc.i.p.ation, whole families of negroes lived upon the produce of one provision ground, and the coco formed the main article of their support. Where the soil is congenial to the white and black Bourbon coco, the labor of one industrious person once a fortnight will raise a supply sufficient for the consumption of a family of six or seven persons. The coco begins to bear after the first year, and with common care and cultivation the same plant ought to give annually two or three returns for several years. In Jamaica, a disease something similar to that affecting the potato, has been found injurious to the coco root. This disease, which has baffled all inquiry as to its origin, affects the plants in and after the second year of their being planted. The first indication of it is the change in the leaves, which gradually turn to a yellow hue, have a sickly appearance, and at length drop off at the surface of the earth. The stock or "coco head," as it is called, below ground, having become rotten, nothing but a soft pulpy ma.s.s remains. In some fields every third or fourth root is thus affected, in others much greater numbers are destroyed, so much so that the field requires to be almost entirely replanted, by which not only an expense is entailed, but a heavy loss sustained, from the field being thrown out of its regular bearing. The black coco seems to suffer less than the white.

Another species, the Taro (_Arum Colocasia_, _Colocasia esculenta_ and _macrorhizon_), is an important esculent root in the Polynesian islands. In the dry method of culture practised on the mountains of Hawaii, the roots are protected by a covering of fern leaves. The cultivation of taro is hardly a process of multiplication, for the crown of the root is perpetually replanted. As the plant endures for a series of years, the tuberous roots serve at some of the rocky groups as a security against famine. It is also extensively cultivated in Madeira and Zanzibar, and has even withstood the climate of New Zealand. It is grown also in Egypt, Syria, and some of the adjacent countries, for its esculent roots. A species is cultivated in the Deccan, for the sake of the leaves, which form a subst.i.tute for spinach. Farina is obtained from the root of _Arum Rumphii_ in Polynesia.

SWEET POTATOES.

The batatas, or camote of the Spanish colonies (_Convolvulus batatas_, Linn; _Batatas edulis_, of Choisy, and the _Ipomaea Batatas_ of other botanists), belongs to a family of plants which has been split into several genera. It is a native of the East Indies, and of intertropical America, and was the "potato" of the old English writers in the early part of the fourteenth century. It was doubtless introduced into Carolina, Georgia, and Virginia soon after their settlement by the Europeans, being mentioned as one of the cultivated products of those colonies as early as the year 1648. It grows in excessive abundance throughout the Southern States of America, and as far north as New Jersey, and the southern part of Michigan. The varieties cultivated there are the purple, the red, the yellow, and the white, the former of which is confined to the South.

The amount of sweet potatoes exported from South Carolina in 1747-48, was 700 bushels; that of the common potato exported from the United States, 1820-21, 90,889,000 bushels; in 1830-31, 112,875,000 bushels; in 1840-41, 136,095,000 bushels; in 1850-51, 106,342,000 bushels.

The sweet potato is cultivated generally in all the intertropical regions, for the sake of its roots, and as a legume in temperate countries. In the Southern States of North America, the culture ceases in Carolina under lat.i.tude 36 degs.; in Portugal and Spain it reaches to lat.i.tude 40 and 42 deg.; and as a legume its cultivation is attempted to the vicinity of Paris. In India it is a very common crop; its tubers are very similar to the potato, but have a sweeter taste, whence the common name; but it must not be confounded with the topinambur (_Helianthus tuberosus_), a native of Brazil, which is less cultivated. The root contains much saccharine and amylaceous matter.

Several marked varieties of the sweet potato are raised in the Polynesian groups. In some islands it forms the princ.i.p.al object of cultivation.

It is grown in the Northern districts of New Zealand, at Zanzibar, Monomoisy, Bombay, and other parts of the East Indies. They are raised on the bare surface of the rock in some parts of the Hawaiian islands, and a sourish liquor is procured from them. It was early cultivated on the Western Coast of Africa, for the Portuguese Pilot (who set out on his voyages to the colony at St. Thomas, in the Gulf of Guinea) speaks of this plant, and states that it is called "batata"

by the aboriginals of St. Domingo. They are abundant at Mocha and Muscat. Sweet potatoes form a princ.i.p.al and important crop in the Bermudas.

A valuable addition has lately been made to the votaries of the sweet potato in Alabama, supposed to be from Peru. A letter describing it says:--"It is altogether different and equally superior to any variety of this root hitherto known. It is productive, and attains a prodigious size, even upon the poorest sandy land, and the roots remain without change from the time of taking them out of the ground until the following May. The plant is singularly easy of cultivation, growing equally well from the slip or vine, the top or vine of the full-grown plant being remarkably small; the inside is as white as snow. It is dry and mealy, and the saccharine principle contained resembles in delicacy of flavor fine virgin honey."

There is in general a great error in cultivating this root, as most people still plant in the old way, two or three sets in the hole, which is a great deal too close.

When a piece of land is to be planted in sweet potatoes, it should be top-dressed with some manure, to be dug or ploughed under a week or two before it is to be planted. Drills should be made two feet apart, and the potatoes placed in the drill about one foot asunder. From eight to twelve to the pound are the best size for planting. The "white upright" kind, when intended for sets, should be taken up early in March, and kept about a month, so as to be quite dry before planting. Abundant crops can rarely be raised from the stem of the "uprights;" the old potato, however, grows to a large size. I have planted a potato weighing about an ounce, and dug it up in August, weighing over two pounds. The drills can be made with a small plough to great advantage, when a person understands it.

The best manure for the sweet potato is anything green, such as fresh seaweed, green oats, bushes, or anything of the kind, put in in abundance.

Care should be taken to get early and good strong slips. A slip with about six joints is quite long enough; three or four joints to be put under ground, and the rest above. For slips, the land must be prepared as already described for the potatoes; this should be done before the slips are ready to cut.

The best way to plant slips is to drill, the same way as for the potatoes, only a little closer; then put the end of the slip in, leaving about two joints out of ground, placing them one foot apart.

The drills can be made in dry weather, so as not to have any delay when it rains; by this means a great many can be planted in a day.

The best land for sweet potatoes is the light sandy kind; a rich friable black mould, or a rocky substratum; for hill sides, rocky ravines, and places which would be called barren and unprofitable for other crops, are found to yield a good return when planted with sweet potatoes. The best time to plant slips to get stock from, is the latter end of August or early in September, as the season may suit.

The sweet potato of Java, says Mr. Crawfurd, is the finest I ever met with. Some are frequently of several pounds weight, and now and then have been found of the enormous weight of 50 lbs. The sweetness is not disagreeable to the palate, though considerable, and they contain a large portion of farinaceous matter, being as mealy as the best of our own potatoes. In Java it is cultivated in ordinary upland arable, or in the dry season as a green crop in succession to rice.

A tuberous root (_Ocymum tuberosum_), an inhabitant of the hot plains, is frequently cultivated in Java. It is small, round, and much resembling in appearance the American potato, but has no great flavor.

Its local name is _kantang_.

Ca.s.sAVA OR MANIOC.

Of this plant, which is a shrub about six feet high, extensively grown for its farinaceous root, there are several species, nearly all natives of America, princ.i.p.ally of Brazil, whence it derives one of its common names of Manihot or Mandioc. Two species of Manihot have been found indigenous in South Australia. The varieties commonly cultivated for their roots, are the sweet and the bitter.

1. Sweet ca.s.sava (_Janiphi_ (or _Jatropha_,) _Loeflingii_, Kunth; _Manihot Aipi_, of Pohl).--This species has a spindle-shaped root brown externally, about six or seven ounces or more in weight, which contains amylaceous matter, without any bitterness, and is used as food, after being rasped and washed, so as to cleanse it from the fibrous matter, in the same manner as arrowroot is prepared. It is distinguished from the bitter ca.s.sava by a tough ligneous fibre, which runs through the heart of the tuber. Manihot starch is sometimes imported into Europe under the name of Brazilian arrowroot. The ca.s.sava is known in Peru as _yucca_.

A dry mixed soil is best suited to its culture. So exhausting is this crop, that it cannot be raised more than two or three times successively on the same land. The roots arrive at maturity in eight or nine months after planting, but may be kept in the ground a much longer time without injury. Sweet ca.s.sava might be sliced, dried in the sun, and sent to Europe in that state. In dry weather the process succeeds remarkably well, and the dried slices keep for a considerable time. Dr. Shier ascertained that when these sliced and dried roots were first steeped and then boiled, they return to very nearly their original condition, and make an excellent subst.i.tute for the potato.

The plant thrives on even the poorest soil; the mode of planting is simple. It consists in laying cuttings a foot long in square pits a foot deep, and covering them with mould, leaving the upper ends open.

From two to four pieces may be placed in each square. The planting ought to be in the rainy season. The cuttings must be made from the full-grown stem. A humid soil causes the root to decay, a dry soil is therefore more adapted for its cultivation. As blossoms are occasionally plucked from potato plants, so the manihot or ca.s.sava is deprived of its buds to increase the size of its roots. The raw root of the bitter species, when taken out of the ground, is poisonous--if exposed, however, to the sun for a short time, it is innocuous, and when boiled is quite wholesome.