Order. Names of specimens.

1. St. Vincent Arrowroot, Commercial 2. Arrowroot, C., C.L.

3. Sweet ca.s.sava, C., C.L.

4. Bitter ca.s.sava, C., C.L.

5. Bermuda arrowroot, Coml.

6. Arrowroot, C., C.L.

7. Irish potato, C.L.

8. Potato starch, Coml.

9. Buck yam, C., C.L.

10. Arrowroot, C.

11. Plantain, C., C.L.

12. Tannia, C., C.L.

13. Sweet potato, C., C.L.

14. Common yam, C., C.L.

15. Tous les mois, Grenada, Cml.

16. Barbados arrowroot, Coml.

17. Tous les mois, C., C.L.

18. Barbados yam, C., C.L.

19. Guinea yam, C., C.L.

20. Wheat starch, Coml.

21. Maize, C., C.L.

On comparing this list with the former one, and taking a general view of the subject, it will be seen that the jellies that are most tenacious are generally the least translucent, and that the order of the two lists is more nearly the converse than occurs in regard to any other properties.

_Percentage of starch yielded by different plants_.--On this point no two writers do or can agree. The quant.i.ty of starch, even in the same plants, the potato for instance, varies with the season, the soil, climate, age, ripeness, length of time the roots have been out of the ground, &c.

In the following table I have given the result of a series of trials made in the Colonial Laboratory, Demerara. The roots were all fresh dug, and, with two exceptions, noticed in the remarks, were fair average specimens. The process was the common one. The grater or rasping machine was of copper, to avoid injuring the color of some of the starches, which an iron grater is liable to do:--

TABLE NO. V.--PERCENTAGE OF STARCH YIELDED BY DIFFERENT PLANTS.

No. Names of plants. Percentage of starch.

1. Sweet ca.s.sava 26.92 2. Bitter ca.s.sava 24.84 3. Another sample 20.26 4. A third 16.02 5. Common yam 24.47 6. Arrowroot (roots scarcely ripe) 21.43 7. Another sample 17.28 8. Barbados yam 18.75 9. Tannia 17.05 10. Another sample 15.35 11. Guinea yam 17.03 12. Plantain 16.99 13. Sweet potato 16.31 14. Buck yam 16.07 15. Another sample 15.63 16. A third, from a dark colored variety 14.83

From the foregoing list it appears that the sweet and bitter ca.s.sava merit attention as starch-producing plants. They are occasionally grown for this purpose in the colonies, and yield a large per centage of starch; but there exists an opinion, whether well or ill founded, that it is liable to rot linen, and the preference is given here to the starch of arrowroot. It remains to be seen, however, what estimate will be formed of this starch in England, for if it should prove an esteemed variety, there can be no doubt of its proving a highly profitable cultivation. Ca.s.sava grows readily in almost any soil, and when the drainage is tolerable, two crops of the sweet variety can, it is stated be grown in a year. I have seen it growing luxuriantly in the light soils of the interior, as well as in the stiff clay soils of the coasts. It is considered an excellent preparatory crop in new and stiff land, on account of its tendency to loosen the soil. Were the bitter variety fixed on, the preparation of _Casareep_ might be combined with the preparation of starch; and as that substance is one of the most esteemed bases for the preparation of various sauces, it is probable that this might turn out the most profitable part of the produce. At all events, bitter ca.s.sava would have this advantage over all other starch-producing roots, that the juice of the roots could be turned, to account as well as the starch.

Of all the plants mentioned in the list, starch is most readily separated from the arrowroot, in consequence of the tissue being more fibrous, and yielding little or no cellular tissue requiring to be run off the starch. Time and water are thus saved in the process, and were the fibrous residue pressed and dried, it could probably be turned to good account in the manufacture of paper.

In respect of facility of preparation, the plantain starch, though of excellent quality, ranks lowest, for the flesh-colored tissue in which the starch is embedded is somewhat denser than the starch, and settles down under it, and it is not a little difficult to arrange the process so as completely to separate the finer parts of this matter from the starch, and hence its color is never perfectly white.

_Yield of starch-producing plants per acre_.--On this subject, as already remarked, I do not at present possess sufficiently accurate data.

In England ten tons of potatoes are not unfrequently produced per acre; now a.s.suming 15 the per centage of starch, there would be a yield of one-and-a-half tons per acre, which, at the-lowest quotation, 28s. a cwt., would give 42 per acre; and were the starch to rank with that prepared from wheat, it would produce 40 per ton, or 60 per acre. In the thorough drained land of Demerara, and under a good system of cultivation, I have no doubt that ten tons of ca.s.sava could easily be grown, and if it yielded 25 per cent. of starch, it would be a return of 2 tons, or of 62 10s. per acre, reckoned at the price of potato starch.

Of the yield of the plantain we possess much more accurate information. A new plantain walk in this colony (British Guiana) will yield 450 bunches, of 50 lbs. each, of which, as nearly as possible, 50 per cent. will be of core, containing 17 per cent. of starch, thus producing 17 cwt. of starch per acre. But an old plantain walk, even when free from disease, could not be reckoned to yield more than half this quant.i.ty, namely, 8 cwt. per acre. Considering the value that is set on the plantain as an article of food, and the difficulties incident to the process of making starch from it, it is by no means probable that it will ever be used as a source from which to obtain starch.

Of the quant.i.ty of arrowroot that can be grown per acre, I have been able (continues Dr. Shier) to procure no information; but from the price it commands in the market, the facility with which it can be grown, and the ease with which the process of separating the starch can be carried on, it deserves a fair trial here. To cultivate it to advantage it ought to be done on thorough-drained and well-tilled land, planted at the proper season, and not dug till ripe and in dry weather.

Of the Tous les mois, I have only been able to procure a single plant, for which I am indebted to the kindness of the Hon. John Croal. As the root was immature, it would be unfair to deduce from the quant.i.ty of starch obtained, the per centage generally contained by the plant. Its immaturity was also indicated by the globules being smaller than in the specimen obtained from Grenada; in other respects, however, such as the tenacity of its jelly, it stands highest. It is altogether one of the most promising starch-producing plants, and obviously deserves a careful trial. It is a plant that expends a good deal of matter in maturing a considerable quant.i.ty of dense and bulky seeds, but as it propagates both by root and seed, it is probable that, as a root-crop, it would be highly advantageous to procure a variety that does not flower.

Both the tannia and the sweet potato can be readily grown, and the produce per acre is large; but from the foregoing tables it would appear that there are other plants whose starch is likely to be held in greater estimation.

_Difficulties attendant on the process of preparing starch_.--Were the manufacture of superior starch to be carried out in this colony (British Guiana) on a large scale and profitably, recourse would require to be had to all the well-known means of economising labor. In the cultivation as much as possible would require to be done by cattle and implement labor, and this would be the easier to accomplish, inasmuch as, to grow roots to great advantage, the land would require to be thorough drained. When the produce was brought to the buildings, machinery similar to what is already in use in Europe, for the purpose of washing and rasping roots, and of separating and washing starch, would suffice with comparatively little manual labor. An ordinary amount of judgment being exercised in determining the proper period of ripeness of the roots, and in selecting seasons when the weather is usually most suitable for conducting the process of manufacture, it does not appear that any unusual difficulty would have to be encountered by growers or manufacturers, unless as regards the obtaining of a sufficient supply of good water; for that is essential to the production of good starch.

The creek water of the colony is generally too brown, and the trench water too muddy, and contains often too much salt to produce starches of the finest color, hence recourse would require to be had to rain water, or Artesian water. The first is remarkably pure, and it certainly does not appear that were sufficiently capacious reservoirs built, or ponds dug, and protected from infiltration by the usual well-known means, there would be great difficulty in getting a sufficient supply of rain water. It is done in Bermuda, and why not here? On the other hand, almost all the Artesian wells in the colony contain a large quant.i.ty of oxide of iron held in solution by carbonic acid, and which separates as an ochrey deposit on free exposure to the air. Were this water used in the starch process, it would certainly injure the color materially; but by a chemical process, exceedingly simple, inexpensive, and easy of application, it is possible to purify the Artesian water, and render it almost as fit as rain water for the purpose of manufacturing starch.

In some of the other colonies a great deal of the best starch is produced by the holders of small lots of land, and many parts of the labor being light, and suited for women and children, it is one of the most desirable cultivations for small holders, and would be very beneficial for Demerara, where the lands of the peasantry too generally lie in a state of utter neglect; yet small holders could not be expected to be able to compete with those who should grow starch on the large scale, and prepare it with the best machinery.

_Ca.s.sava meal, plantain meal, &c., as articles of export_.--It may soon become an important question whether the plantain, or some of the edible roots grown in the tropics, might not be sent to Europe in a fresh state as a subst.i.tute for the potato. Many of them, the buck yam and the ca.s.sava, for instance, ought to be used when fresh dug, for every day they are out of the ground they deteriorate. This, however, is not so much the case with some of the larger yams. It is worth trying whether the finer sorts that deteriorate by keeping, might not, after being sliced and dried in the sun, become articles of export, either in that state or when ground to meal. For this purpose the bitter ca.s.sava, the plantain, and the buck yam are the most promising.

Of the bitter ca.s.sava mention has already been made as a substance from which the starch and _casareep_ might be prepared. In this case, however, the woody and cellular tissue, with the small quant.i.ty of starch left in it by the ordinary starch process, would form far too poor an article of diet to const.i.tute part of the food of man. But the roots might be used as a medium from which to prepare ca.s.sava meal, _casareep_, and the very small quant.i.ty of starch which is expressed along with the juice, leaving all the rest of the starch to form part of the meal. It is of such meal that the ca.s.sava cakes of the Indians are prepared; and although by no means so nutritive as Indian corn meal[46], there can be little doubt that in the Scotch and Irish markets the ca.s.sava meal would obtain a preference; and were it exported in quant.i.ty it would probably come into extensive use among all cla.s.ses.

The process would be as follows:--After washing in a revolving apparatus, by which means the adherent earth would be got quit of, and almost the whole of the thin dark colored cuticle become detached, the roots could be reduced to pulp in a rasping-mill, without the use of water; the pulp might be compressed in bags by hydraulic pressure, whereby the juice, together with a small portion of the starch, would be expressed. After allowing the starch to subside, the juice should be concentrated to about the density of 1.4. The starch would be washed, purified, and dried. The contents of the bags would then be broken up and dried in the sun or in a current of air, after which the meal would be sifted through a coa.r.s.e sieve to separate the coa.r.s.er parts, which, if their amount was considerable, could be ground and added to the rest. In this state of rough meal it is fit for making the ca.s.sava cakes. If ground to flour it might be used to mix with wheat, rye, or barley flour.

The process is usually conducted as follows:--The squeezed pulp is broken up, sifted, and exposed to the sun on trays or mats till it is fully more than half dry. An iron hoop of the size and thickness of the cake to be made is then laid on a griddle or hot plate, and the s.p.a.ce within the hoop is filled evenly with the somewhat moist meal, no previous kneading or rolling having been employed. As soon as the coa.r.s.e meal coheres, the ring is lifted and the cake is turned and heated on the opposite side. The heat should not be sufficient to brown the cake. The cakes are finally dried by exposure to the sun.

From the dry ca.s.sava meal cakes may be prepared by sprinkling it with as much cold water as to moisten it to the proper point, and then proceeding as above. Hot water cannot be employed, neither can kneading, or any considerable degree of compression be used, otherwise the water does not evaporate readily enough; the starch gets too much altered by the heat, and the cake becomes tough.

If an acre of well-tilled thorough-drained land yield 10 tons of fresh roots, and I have every reason to believe that such a return might be obtained, I have ascertained that the produce would be 3 tons of meal, 598 lbs. of _casareep_, and 2 cwt. of starch; and estimating the meal at 1d. per lb., the _casareep_ at 1s. 5d. per lb., and the starch at 40s. per cwt., the gross amount would be 78 13s. 4d. per acre. In ascertaining these proportions, very simple machinery was employed, and had the pulp been better pressed the quant.i.ty of _casareep_ would have been considerably greater.

From the table given in a former note it will be seen that the ca.s.sava meal prepared in this way contains but a very small proportion of matter nutritive in the sense of contributing to the formation of blood, and that the expressed juice carries off fully one-half of the proteine compounds contained in the plant.

Lichenin is a variety of starch occurring in _Cetraria islandica_, or Iceland moss.

_Indian corn starch_.--The advance of science has recently brought to our knowledge the preparation and use of another article, not only important as food, but also essential in the arts. I have had occasion to mention the high value of the Indian corn, and I might with advantage allude to many of its uses and properties; at present I must confine my remarks to a product from this valuable grain, known as corn starch, and yet another as the fecula of maize. In the close of 1849, Mr. Willard and his a.s.sociates, of Auburn, established extensive works at Oswego, for the preparation of these important products, their establishment covering an area of 49,000 square feet. As the proprietors have to some extent held unrevealed the process by which they produce a starch more pure than the starch of commerce, we may not indulge in speculative curiosity; yet I can hardly doubt their great success is mainly attributable to perfect machinery, guided by science and talent. The rapid and extended demand for these new products presents sufficient evidence of their character, as we are told that about three millions of pounds of this corn starch are demanded annually by the trade, notwithstanding the usual supply of wheat starch is undiminished. A remarkable feature of maize starch is the absence of impurities; upon being subjected to a.n.a.lysis, it is found that only 2 76-100 parts in 1000 are of other matter than pure starch. According to Dr. Ure, wheat yields only 35 to 40 per cent, of good starch, a material extensively used in arts and manufactures.

In addition to starch, the Oswego starch-factory produces from Indian corn a fecula, peculiarly adapted to culinary purposes, presenting to our domestic economy one of the most acceptable, pure, and nutritious articles of food. Already has it become an indispensable household article, and is consumed largely at home and abroad. The factory, though in its infancy, consumes annually 150,000 bushels of corn, equal to about nine millions of pounds in weight. Hitherto the quant.i.ties of starch used for laundry purposes and in the manufactories of America, have been produced from costly wheats, though it may be found in many vegetable substances, such as potatoes, the horse chesnut and other seeds. In England, where breadstuffs, particularly wheat, have been raised in quant.i.ties inadequate to the demand for food, attempts have been made to convert the viscid matter of lichens into a gum, for the use of calico printers, paper-makers, and ink makers; for the stiffening of silks, c.r.a.pes, and the endless variety of dry goods, which, by means of these gums or starch, are made to appear of greater consistency. Most of these attempts had partial success, yet the making of starch from wheat has not been arrested.

The Oswego starch factory has happily introduced the use of Indian corn, as a grain producing a larger proportion of pure amylaceous properties than any other known vegetable substance, proffering to the American manufacturer another economic advantage, sustaining, in a most legitimate matter, sound rivalry and compet.i.tion with all the world. I am not aware whether the Oswego factory has converted its starch into gum--a process easily accomplished by heat, and thus rendered soluble in cold water, which cannot be done while in its condition of starch. Here is another result of vast importance derivable from Indian corn; and we can well conceive that, in a short period of time, the advantages now derived from the production of corn starch, may have grown into a national benefit.

Rice (according to Prof. Solly) contains on an average about 84 per cent of starch; but till comparatively a few years ago, no starch was manufactured from it, notwithstanding its low price, and the large quant.i.ty of starch which exists in it. The reason of this was, that the old process of fermentation, by means of which starch is procured from grain, was not found to be applicable to rice; and hence the latter only became available as a source of starch in 1840, when Mr.

Orlando Jones introduced his new process, for which he obtained a patent. This process consisted in macerating the rice for about 20 hours in a dilute solution of caustic potash, containing about 200 grains of the alkali in every gallon; the liquor is then drawn off, the rice dried, reduced to powder by grinding, then a second time digested in a similar alkaline lye for 24 hours, repeatedly agitated.

After this it is allowed to settle, and well washed with pure cold water. A prize medal was awarded for this rice starch at the Great Exhibition.

Mr. S. Berger, of Bromley, also received a prize medal. He adopts a different mode of preparation. In place of employing a dilute solution of caustic potash to dissolve the gluten and other insoluble matters of the grain, Mr. Berger uses a solution of carbonate of soda, containing half a pound to the gallon. The rice is steeped, in cold water for 48 hours, levigated in a suitable mill, and the pulp thus formed is treated with the solution of carbonate of soda for 60 or 70 hours, being repeatedly stirred; it is then allowed to settle for some hours, the alkaline liquor is drawn off, and the starch is washed and purified. This process was patented by Mr. Berger, in December, 1841.

A third process was patented in February, 1842, by Mr. J. Colman; he uses dilute muriatic acid for the same purpose as Messrs Jones and Berger.

ARROWROOT, EAST AND WEST INDIAN.

The genuine arrowroot of commerce is the produce of the tuberous rhizomata of _Maranta arundinacea_, a native of South America, and _M.

indica_, indigenous to the West Indies, but also cultivated in the East. The best West Indian arrowroot comes from Bermuda. Its globules are much smaller and less glistening than those of _Tous-les-mois_, or potato starch.

The peculiar characteristics of the starch obtained from various plants has been particularised and described already in the elaborate investigation of the commercial yield and value of the starch-producing plants. Amylaceous matter of a similar kind to arrowroot is obtained from other species of Maranta, as from some species of _Canna_, well known under the popular name of Indian shot, from the similarity of their round black seeds.

The arrowroot plant (_M. arundinacea_) is a perennial, its root is fleshy and creeping, and very full of knots and numerous long white fibres. Arising from the root are many leaves, spear-shaped, smooth on the upper surface and hairy beneath. The length of the leaf is about six or seven inches, and the breadth about three towards their base, the color and consistence resembling those of the seed. From the root arise slender petioles upon which the leaves stand, and several herbaceous erect stalks come out between them, rising to the height of about two feet. A loose bunch of small white flowers is succeeded by three-cornered capsules, each containing one hard rough seed.

The propagation and culture of this plant are of the simplest kinds.

The roots should be parted, and the most suitable soil is a rich loam.