Chapter XXX: Section II (8)

In the following observations (continues Dr. Shier) I shall be able to reply to several of these questions, especially those capable of being settled in the laboratory. On other points, particularly those relating to the returns per acre, I am at present but imperfectly informed, in consequence of the limited extent to which these plants have hitherto been cultivated in this colony (Demerara), and from the total absence of authentic data regarding the amount of yield.

_Characters of starch produced from different plants_.--Starches from different plants are best distinguished from one another by examination under a good miscroscope. The grains or globules may be examined either as transparent or opaque objects; and although in the same species there are considerable differences in size and form, the different kinds are, on the whole, quite distinguishable. One of the best ways of examining the form of the globules, under the microscope, is to lay them on a plate of glass and cover them with a drop of aqueous solution of iodine, which renders them gradually blue and opaque. When the difference in size and form between the globules of different species is considerable, as between the _Tous les mois_ starch and cassava starch, or even between the arrowroot starch and cassava starch frequently used to adulterate it, it is not difficult, with a little practice, to detect the fraud.

TABLE ILLUSTRATIVE OF THE SIZE AND FORM OF THE STARCH GLOBULES OF VARIOUS PLANTS.

1. Tous-les-mois (_Canna coccinea_).--Grown in Grenada, 1-300 to 1-2,000 of an inch; general size, 1-500; form of the globules, large, elliptical and ovate, and remarkably transparent.

2. Ditto ditto (species unknown).--From a plant grown in the garden of the Hon. J. Croal, Georgetown, but gathered before the root was fully ripe; globules spherical, shortly ovate and elliptical; size, from 1-600 to 1-1,600; general size, 1-800.

3. Buck Yam (_Dioscorea triphylla_).--Grown on the banks of the Demerara River. Form of globules, elliptical, often truncated at one end, so as to be mullar-shaped, some pear-shaped; length, twice the width; size, 1-600 to 1-2,000; general size, 1-800.

4. Common Yam (_D. sativa_).--Grown on No. 1 Canal, Demerara River. Elliptical, some long elliptical; size, 1-700 to 1-2,000; general size, 1-1,000.

5. Guinea Yam (_D. aculeata_).--Grown in the same locality. Larger globules, elliptical; smaller ditto, spherical, often truncated; some shortly ovate, with the appearance of being flattened; general size and range, same as No. 4.

6. Barbados Yam, grown on banks of Demerara river. Globules, pear-shaped and mullar-shaped; range, 1-700 to 1-1,600; general size, 1-1,000.

7. Plantain (_Musa paradisiaca_).--Grown on the banks of the Demerara river. Globules long and narrow, generally long elliptical, often more acute at the ends than in any other species, some linear ended abruptly; length, often three times the width; range, from 1-400 to 1-4,000 of an inch; general size, 1-800.

8. Potato (_Solanum tuberosum_).--Irish tubers, from Belfast Sound. Globules, 1-600 to 1-2,000; general size, 1-1,200.

9. Potato (Commercial).--Locality unknown. Range from 1-600; globules generally same as former, but a few stray ones as large as 1-40 of an inch.

10. Sweet Potato (_Convolvulus Batatas_).--Grown at the Lodge, Demerara. Form of globules, spherical aggregated; range, 1-1,000 to 1-4,000; general size, 1-2,400.

11. Arrowroot (_Maranta arundinacea_).--Specimens from Bermuda, where the highest priced and best quality is prepared. Ovate and elliptical; length in the larger globules, twice the width; range, from 1-800 to 1-2,400; general size, 1-1,400.

12. Ditto ditto, grown on plantation Turkeyen, Demerara, by J.W. King. Size and description same as No. 11.

13. Ditto ditto, grown and prepared in Barbados. Characteristics the same, but globules more uniform in size.

14. Ditto ditto, grown on plantation Enmore; not quite so uniform in size.

15. Bitter Cassava (_Janipha Manihot_).--Grown on Haagsbosch plantation. A few globules occur as large as the 1-1,000 of an inch; these are ovate, the rest are spherical. The range is from 1-2,000 to 1-8,000; general size, 1-4,000.

16. Sweet Cassava (_Janipha Loeflingii_).--Grown on No. 1 Canal, Demerara River.

17. Tannia (_Caladium sagittifolium_).--Grown at the Lodge. Globules not so truly spherical as the foregoing, but range and size the same.

18. Wheat (_Triticum sativum_).--Locality unknown. Form of globules, spherical and slightly elliptical, some very small; range, 1-2,000 to 1-6,000, the former the general size.

19. Maize (_Zea Mays_).--Grown in the colony, but locality uncertain. Globules, approaching to spherical, much aggregated; range, 1-2,000 to 1-4,000; general size, 1-3,000.

From an inspection of this list, it does not appear that the species would be easily distinguishable, and it is not easy briefly to describe the differences; in practice, however, and especially when the observer has a number of pure and authentic specimens before him, to have recourse to as standards of comparison, the discrimination is by no means difficult.

_Specific gravity of starch derived from various plants_.--Of many bodies the determination of the specific gravity is one of the best modes of distinguishing the purity. With the view of ascertaining whether the different varieties of starch have all the same density, as has been asserted by some, trials were carefully made of as many specimens as I could procure. The results are embodied in the following table:--

TABLE No. I.--DENSITY OF STARCH DERIVED FROM VARIOUS PLANTS.
------------------+-------+-------+-----------------------------------------
| |Tem. at|
Names of |Density|time of| Remarks
Plants | |Obs. F.|
------------------+-------+-------+------------------------------------
1. Bitter cassava|1.4 3 | 87. |Grown in the colony and prepared in
| | | the Colonial Laboratory.
2. Tannia |1.4773 | 87. |Ditto ditto
3. Arrowroot |1.4772 | 86.25 |Ditto ditto
4. Arrowroot |1.4748 | 86.25 |Ditto ditto
5. Common yam |1.4733 | 83.25 |Ditto ditto
6. Sweet potato |1.4718 | 85.75 |Ditto ditto
7. Arrowroot |1.4717 | 82.75 |St. Vincent's, commercial
8. Arrowroot |1.4701 | 84.75 |Grown in the colony and prepared in C.L.
9. Tous les mois |1.4698 | 85.25 |Ditto ditto
10. Sweet cassava |1.4692 | 86.5 |Ditto ditto
11. Wheat starch |1.4632 | 85. |Commercial, of English manufacture
12. Plantain |1.4615 | 85.75 |Grown in the colony and prepared in C.L.
13. Tous les mois |1.4611 | 84.25 |Grenada, commercial
14. Barbados yam |1.4607 | 83.5 |Grown in the colony and prepared in C.L.
15. Irish potato |1.4589 | 84.75 |Tubers from Belfast; prepared in C.L.
16. Guinea yam |1.4581 | 84.2 |Grown in the colony and prepared in C.L.
17. Potato |1.4561 | 84. |Commercial
18. Buck yam |1.4489 | 81.25 |Grown in the colony and prepared in C.L.
19. Arrowroot |1.4443 | 85.5 |Barbados, commercial
20. Arrowroot |1.4158 | 86.25 |Bermuda, ditto
21. Maize |1.4109 | 85.5 |Grown in the colony and prepared in C.L.
------------------+-------+-------+----------------------------------------

From this it will be seen that the order of density does not correspond with the order in any of the other tables. Probably those specimens prepared from dry seeds, such as wheat and maize starch, which, as commercial articles at least, are less pure than those prepared from recently dug roots, have also the lowest density.

_Hygroscopic properties of starch produced from different plants_.--Such of the specimens as are marked in the following table, as prepared in the colonial laboratory, were dried in the sun in shallow trays, to which they had previously been transferred in the wet state. When sun dried, the masses were broken down, and the starches freely exposed to the air in the shade for ten days. Any adherent masses were then rubbed to powder by light pressure in a glazed mortar, and the whole sifted. Portions of each of these starches, and of others for the sake of comparison, were then dried, at 212 degrees Fahrenheit, in a current of dry air, and the loss determined:--

TABLE No. II.--SHOWING THE HYGROSCOPIC WATER CONTAINED BY STARCH
PRODUCED FROM DIFFERENT PLANTS.

Per centage of water. Remarks.
1. Potato 20.27 Commercial, locality unknown
2. Sweet potato 19.57 C., C.L.**
3. Buck yam 19.43 C., C.L.
4. Barbados yam 19.40 C., C.L.
5. Arrowroot 18.81 Bermuda, commercial
6. Irish potato 17.28 Tubers from Belfast, C.L.
7. Guinea yam 17.14 C., C.L.
8. Tous les mois 16.74 Grenada, commercial
9. Arrowroot 16.43 Barbados, ditto
10. Common yam 16.36 C., C.L.
11. Plantain 16.23 C., C.L.
12. Arrowroot 15.65 C., C.L.
13. Arrowroot 14.84 C., Plantation Enmore
14. Tous les mois 14.64 C., C.L.
15. Tannia 14.60 C., C.L.
16. Sweet cassava 14.30 C., C.L.
17. Maize 14.22 C., C.L.
18. Arrowroot 13.36 C., C.L.
19. Bitter cassava 11.88 C., C.L.
20. Wheat starch 11.16 Commercial, of English manufacture

[** The initial C. throughout these tables indicates that the plant
was grown in the colony; C.L., that the starch was prepared in the
colonial laboratory.]

That the extremes in this table should occur in the case of the starches of commerce, was, perhaps, to be expected; nevertheless the difference between the starch of the sweet potato and that of the bitter cassava is nearly as great, and both these specimens were prepared in the laboratory, by the same process, and subject to the same temperature and exposure.

_Characters of the jellies formed by various starches._--_Tenacity_.--I have met with no very precise results on this subject, except the well-known fact that it takes a much larger quantity of some starches, the arrowroot for instance, to form a jelly of equal tenacity with that formed by others, such as the _Tous les mois_; and hence in the West Indies the latter is universally preferred to the cassava starches.

After trying various plans, the method which I found best fitted for comparing the tenacity of different starch jellies, was the following:--Of each of the kinds of starch, 24 grains were weighed out and mixed with 400 grains of distilled water, in a porcelain capsule of suitable size. The mixture was then heated and boiled briskly for three minutes, with constant stirring, and was immediately poured into a conical test-glass,[45] which the jelly nearly filled. The time at which each glass was filled was noted, and exactly two hours were allowed for the contents to cool in a current of air. The glass is then set on a plate of glass, supported on a ring of a retort stand, and the weight ascertained, which was necessary to force a metallic disc, of ascertained size, through the jelly. The most convenient way of doing this was by using a piece of apparatus of the form rudely represented on the margin. The rectangular frame is of thin brass wire, and the slightly cup-shaped disc, _d d_, is soldered to a wire, attached to the upper short side of the rectangle. From the opposite or lower side of the rectangle a small glass cup, _c._, is suspended, into which weights are put as soon as the disc has been made to rest on the surface of the jelly, _pp_ is the plate of glass on which the test-glass is set. Whenever the disc tears the skin of the jelly and begins to sink in it, no further addition, of weights is made, and the weight of the disc, framework, and cup being known, we have an estimate of the tenacity of the jelly. This process is but approximative, and some practice is necessary before the operator succeeds in getting uniform results from the same series of specimens.

+--------------------+
| | |
| | |
| | |
| d \_____/ d |
| |
| |
| |
| p--------------p |
| |
| |
+--------------------+
|
|
|
|
---------
c.

The following statement shows the results on such specimens as I could procure. The disc was exactly 7/10ths of an inch in diameter.

TABLE NO. III.--TENACITY OF STARCH IN JELLIES.

No. Names of specimens. Weight in grains required
to break the jelly.
1. Tous les mois, C., C.L. 2,446*
2. Tous les mois, Grenada, Commercial 1,742
3. Maize, C., C.L. 955
4. Barbados yam, C., C.L. 895
5. Irish potato, from Belfast, C.L. 756
6. Tannia, C., C.L. 630
7. Bermuda arrowroot, finest Commercial 627
8. Common yam, C., C.L. 657
9. Guinea yam, C., C.L. 571
10. Plantain, C., C.L. 467
11. Potato starch, Commercial 467
12. Arrowroot, C., C.L. 393
13. Sweet potato, C., C.L. 368
14. Arrowroot, C., C.L. 340
15. Arrowroot, C. 301
16. Arrowroot, St. Vincent's, Commercial 289
17. Barbados arrowroot, Commercial 273
18. Wheat starch, Commercial 183
19. Buck yam, C., C.L. 151
20. Bitter cassava, C., C.L. 150
21. Sweet cassava, C., C.L. 78

[* In this instance the weight stated detached the jelly from the side of the glass, but the skin of the jelly was not torn as in the other cases.]

From this list it is obvious that, in respect of tenacity, there is a very great difference between the jellies prepared from the different starches--greater, indeed, than exists in regard to any other character. At first I thought it probable that the tenacity of the jelly would bear some relation to the size of the globules, and it is true that we find the Grenada Tous les mois, the largest globule, next the top, and the cassava among the smallest, at the bottom of the scale. But, on the other hand, we have the Buck yam starch, a large sized globule, very high; together with many other exceptions.

As an article of diet, the most tenacious varieties of starch are preferred, on account of the economy of employing an article of which a less quantity will suffice; and the same is true when applied to starching linen, provided the jelly be not deficient in clearness.

_Clearness of jellies_.--When starch jelly is used for the purpose of starching, or glazing linen, or cotton goods, those varieties that are most transparent are understood to be preferred, provided, at the same time, they possess the requisite tenacity. This and other matters will be best determined by practical men in England; but having had occasion many times to prepare specimens for trying the tenacity, the opportunity was always taken of arranging the specimen of jellies in the order of their clearness, or, to speak more accurately, of their translucency. In this respect also they exhibit considerable differences, varying, when prepared according to the formula described under the head of tenacity, from very translucent approaching to opaque. The order is shown in the annexed list, which begins with the clearest.

TABLE NO. IV.--SHOWING THE ORDER OF CLEARNESS OR TRANSLUCENCY OF
UNIFORMLY PREPARED STARCH JELLIES.

Order. Names of specimens.
1. St. Vincent Arrowroot, Commercial
2. Arrowroot, C., C.L.
3. Sweet cassava, C., C.L.
4. Bitter cassava, 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 quantity 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 cassava 26.92
2. Bitter cassava 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 cassava 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. Cassava 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 cassava 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 assuming 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 cassava could easily be grown, and if it yielded 25 per cent. of starch, it would be a return of 2½ 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 quantity, namely, 8½ 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 quantity 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 quantity 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 quantity 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 quantity 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.

_Cassava 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 substitute for the potato. Many of them, the buck yam and the cassava, 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 cassava, the plantain, and the buck yam are the most promising.

Of the bitter cassava 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 quantity of starch left in it by the ordinary starch process, would form far too poor an article of diet to constitute part of the food of man. But the roots might be used as a medium from which to prepare cassava meal, _casareep_, and the very small quantity 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 cassava 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 cassava meal would obtain a preference; and were it exported in quantity it would probably come into extensive use among all classes.

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 coarse sieve to separate the coarser 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 cassava 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 space within the hoop is filled evenly with the somewhat moist meal, no previous kneading or rolling having been employed. As soon as the coarse 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 cassava 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 3½ 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 quantity of _casareep_ would have been considerably greater.

From the table given in a former note it will be seen that the cassava 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 associates, 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 analysis, 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 quantities 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 quantities 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, crapes, 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 competition 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 quantity 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.

In the Bermudas, a deep rich soil, or one in which marsh or peat prevail, is alone adapted for growing arrowroot in perfection.

A correspondent from the Bermudas, (where arrowroot forms the great staple crop of the islands), informs me that he ploughed up a small piece of land, twenty rods (or the eighth part of an acre), with a small plough and one horse. He ploughed it over three times, and the third time planted the arrowroot as he ploughed it. The land had not been turned up before for twenty years.

The expenses and profits stand thus:--

EXPENSE.
£. s. d.
To the ploughman, harrowing and planting the
arrowroot 1 0 0
Arrowroot plants 16 0
Digging it up £1 0 0
Deduct half, as the land was planted for the next
year 0 10 0 0 10 0
Balance carried down, being net profit 5 14 0
--------
8 0 0
PRODUCE.
By 2,000 lbs. of root at 8s. per 100 lbs. 8 0 0
By balance brought down as net profit 5 14 0

The above £5 14s. clear profit on the 20 rods, is at the rate of £45 12s. profit for one acre. Now, if a small cultivator were to plant three or four acres, and get only one-half of the above profit, it would give a good return, and would be well worth the trial.

Arrowroot requires a good rich red soil, of which there is still much lying waste. The best time for planting it is in April, but it can be planted in March, or indeed at any time after the first of the year, till May: though if taken up and planted before Christmas, you may depend it will not come to any perfection. Arrowroot can be planted in many ways; either in holes made with a hoe, ploughed under, or in drills like Irish potatoes. Now the way I prefer is to prepare the land, then strike the line at two feet apart, and make holes with a pointed stick or dibble six inches apart, putting in each hole one strong plant or two small ones, then cover them up. This is more trouble than the old way, but it gives an excellent crop. It can also be planted like Irish potatoes in drills, two feet apart in the rows, and six inches between the plants. It should be hand-weeded in the spring, because if it is hoed, most likely you will cut some of it off which may be springing under ground, and it will never come up so strong again. Arrowroot requires very strong ground and plenty of manure. Farm yard manure is the best; next to that green seaweed dripping with salt water--this is an excellent manure, and should be dug in the ground as the arrowroot is taken up. I have no doubt that it would be of great advantage to the planter, if he were to put a cask in a cart, fill it with salt water, and put it on the land a few weeks before it is planted. Some people say that arrowroot does not pay so well, because it has to stay in the ground a whole year; but then if you have onions you can plant them over it, and so obtain a crop which will pay much better than the arrowroot itself. If you have a large piece of arrowroot ground, take up one half early, and plant it out with Irish potatoes; then take up the other half later, and with the plants set out your potato ground, that is if you have taken up your potatoes; if not, plant the arrowroot between the rows, in holes; so that when you take up the potatoes, you clean the arrowroot and loosen the ground, which will give a good crop; or you can plant Indian corn very thin over the arrowroot ground (if you have nothing else), but be sure to cut it up before it ripens corn, or it will injure your arrowroot crop; or you may plant a few melon seeds over it, and you will have a fine crop of fruit.

In 1845 I planted, in the months of January and February, a quarter of an acre of good land, in arrowroot and onions.

The expense and profit stand as follow.--

EXPENSE
£. s. d.
To digging the ground 1 0 0
Planting arrowroot 0 6 0
Twelve load of seaweed, at 1s. 0 12 0
Rotten manure for onions, 10 loads, at 2s. 1 0 0
One bottle onion seed 0 16 0
Sowing onion seed and keeping the plants clean 0 10 0
Planting out onions 1 0 0
Cleaning onions after set out 0 15 0
Tops and making basket 1 8 0
Pulling, cutting, and basketing 0 18 0
Carting and shipping 0 8 0
Digging arrowroot 2 0 0
--------
10 13 0
Clear profit on quarter acre 22 13 9
--------
33 6 9
PRODUCE
By onions sold 20 16 0
By arrowroot 12 10 9
--------
33 6 9

This is at the rate of £90 15s. clear profit per acre, which is more than double the worth of the land. I have not named the arrowroot plants, because I have planted my land with them again, but they might be fairly put to the credit of the account. The above statement shows what may be done with good land and good management; but even if a man can only clear £10 on an acre of land, he ought not to grumble.

Dr. Ure gives a most interesting and lucid account of the mode of manufacture in the island of St. Vincent, where the plant is now cultivated with great success, and the root manufactured in a superior manner.

It grows there to the height of about three feet, and it sends down its tap root from twelve to eighteen inches into the ground. Its maturity is known by the flagging and falling down of the leaves, an event which takes place when the plant is from ten to twelve months' old. The roots being dug up with the hoe, are transported to the washing-house, where they are thoroughly freed from all adhering earth, and next taken individually into the hand and deprived, by a knife, of every portion of their skins, while every unsound part is cut away. This process must be performed with great nicety, for the cuticle contains a resinous matter, which imparts color and a disagreeable flavor to the fecula, which no subsequent treatment can remove. The skinned roots are thrown into a large cistern, with a perforated bottom, and there exposed to the action of a copious cascade of pure water, till this runs off quite unaltered. The cleansed roots are next put into the hopper of a mill, and are subjected to the powerful pressure of two pairs of polished rollers of hard brass; the lower pair of rollers being set much closer together than the upper. The starchy matter is thus ground into a pulp, which falls into the receiver placed beneath, and is thence transferred to large fixed copper cylinders, tinned inside, and perforated at the bottom with numerous minute orifices, like a kitchen drainer. Within these cylinders, wooden paddles are made to revolve with great velocity, by the power of a water-wheel, at the same time that a stream of pure water is admitted from above. The paddle-arms beat out the fecula from the fibres and parenchyma of the pulp, and discharge it in the form of a milk through the perforated bottom of the cylinder. This starchy water runs along pipes, and then through strainers of fine muslin into large reservoirs, where, after the fecula has subsided, the supernatant water is drawn off, and fresh water being let on, the whole is agitated and left again to repose. This process of ablution is repeated till the water no longer acquires anything from the fecula. Finally, all the deposits of fecula of the day's work are collected into one cistern, and being covered and agitated with a fresh change of water, are allowed to settle till next morning. The water being now let off, the deposit is skimmed with palette knives of German silver, to remove any of the superficial parts, in the slightest degree colored; and only the lower, purer, and denser portion is prepared by drying for the market.

On the Hopewell estate, in St. Vincent, where the chief improvements have been carried out, the drying-house is constructed like the hot-house of an English garden. But instead of plants it contains about four dozen of drying pans, made of copper, 7½ feet by 4½ feet, and tinned inside. Each pan is supported on a carriage having iron axles, with _lignum vitæ_ wheels, like those of a railway carriage, and they run on rails. Immediately after sunrise, these carriages, with their pans, covered with white gauze to exclude dust and insects, are run out into the open air, but if rain be apprehended they are run back under the glazed roof. In about four days the fecula is thoroughly dry and ready to be packed, with German silver shovels, into tins or American flour barrels, lined with paper, attached with arrowroot paste. The packages are never sent to this country in the hold of the ship, as their contents are easily tainted by noisome effluvia, of sugar, &c.

Arrowroot is much more nourishing than the starch of wheat or potatoes, and the flavor is purer. The fresh, root consists, according to Benzon, of 0.07 of volatile oil; 26 of starch (23 of which are obtained in the form of powder, while the other 3 must be extracted from the parenchyma in a paste, by boiling water); 1.48 of vegetable albumen; 0.6 of a gummy extract; 0.25 of chloride of calcium; 6 of insoluble fibrine; and 65.6 of water.

Arrowroot is often adulterated in this country with potato flour and other ingredients.

Dr. Lankester asserts that the value of arrowroot starch, as an article of diet, is not greater than that of potato starch, and that the yield of starch is not greater from the arrowroot than from potatoes; but this I must decidedly deny. Chemical analysis and experience are proofs to the contrary.

The analogy arrowroot has to potato starch, has induced many persons to adulterate the former substance with it; and not only has this been done, but I have known instances in which potato starch alone has been sold for the genuine foreign article. There is no harm in this, to a certain extent; but it certainly is a very great fraud upon the public (and one for which the perpetrators ought to be most severely punished), to sell so cheap an article at the same price as one which is comparatively costly. There is, moreover, in potato starch, a peculiar taste, bringing to mind that of raw potatoes, from which the genuine arrowroot is entirely free. This fraud, however, can be readily detected; arrowroot is not quite so white as potato starch, and its grains are smaller, and have a pearly and very brilliant lustre; and further, it always contains peculiar clotted masses, more or less large, which have been formed by the adhesion of a multitude of grains during the drying. These masses crush very readily when pressed between the fingers, and as before stated, arrowroot is free from that peculiar odor due to potato starch. This may be most readily developed by mixing the suspected sample with hot water; if it be genuine arrowroot, the mixture is inodorous, if potato starch, the smell of raw potatoes is immediately developed. If a mixture of arrowroot and potato starch be minutely observed by means of a good microscope, the grains of arrowroot may be readily detected; they are very small and exceedingly regular in shape, whilst those of potato starch are much larger, and very irregular in shape. But the most convenient and delicate test of all, is that proposed by Dr. Scharling, of Copenhagen. After mentioning the test by the microscope, he goes on to state that he has obtained more favorable results by employing diluted nitric acid; and that, if arrowroot or potato starch be mixed with about two parts of concentrated nitric acid, both will immediately assume a tough gelatinous state. This mass, when potato starch is employed, is almost transparent, and when arrowroot is used, is nearly opaque, as in the case above mentioned, in which hydrochloric acid is substituted. A mixture of nitric acid and water, however, operates very differently on these two kinds of starch. The glutinous mass yielded by the potato starch, becomes in a very brief period so tough that the pestle employed for stirring the mixture is sufficiently agglutinated to the mortar, that the latter may be lifted from the table by its means. Arrowroot, on the other hand, requires from twenty-five to thirty minutes to acquire a like tenacity.

The _Lancet_ recently stated that, on a microscopical analysis of 50 samples of arrowroot, purchased indiscriminately of various London tradesmen, 22 were found to be adulterated. In 16 cases this adulteration consisted in the addition of a single inferior product much cheaper in price, such as potato flour, sago meal, or tapioca starch, while in other instances there was a combination of these articles, potato flour being usually preponderant. Ten of the mixtures contained scarcely a particle of the genuine Maranta or West India arrowroot, for which they were sold. One consisted almost wholly of sago meal; two of potato flour and sago meal; two of potato flour, sago meal, and tapioca starch; one of tapioca starch; and four of potato arrowroot, or starch entirely. The worst specimens were those which were done up in canisters especially marked as "Genuine West India arrowroot," or as being "warranted free from adulteration;" and one, which contained a considerable quantity of potato flour, was particularly recommended to invalids, and certified as the finest quality ever imported into this country. The profits to the vendors of the inferior compounds are to be estimated from the fact that the price of sago meal and potato starch is about 4d. per lb., while the genuine Maranta arrowroot is from 1s. to 3s. 6d. per lb.

The arrowroot of Bermuda has long borne a high reputation, being manufactured on a better principle and being therefore of superior quality to that produced in Antigua, St. Vincent, and other West Indian islands. The process is tedious and requires a good deal of labor. There is no doubt, however, that the quality of the water has a great deal of influence on the fecula. Bermuda arrowroot is necessarily made from rain water collected in tanks or reservoirs, and the lime and the deposit from houses, &c., may alter its properties. After the root is taken from the ground it is placed in a mill, and is thereby cleansed of its exterior excrescences; it is then thoroughly washed, when it is ready for the large machine, the principle of which is similar to the "treadmill." A horse is placed on something like a platform, and as he prances up and down, the machinery is set in play. A person stands at the end, and places the root in the wheel of the machine, which, after being ground, falls into a trough of water. After going through this process, it is rewashed and then placed in vessels to dry in the sun. It is packed in boxes lined with blue paper or tin, and sent to the markets in England and America, where it generally meets with ready sale.

At a meeting of the Agricultural Society of Bermuda, held in May, 1840, Mr. W.M. Cox submitted a new arrowroot strainer which he had invented. It consists of two cloth strainers fixed to hoops from 15 to 20 inches in diameter. The strainers working one within the other, are kept in motion by a lever, moved by hand. The whole apparatus is not an expensive one, and is well adapted for aiding the manufacture of arrowroot upon an expeditious and economical plan.

A simple method by which starch may be extracted from the fecula with much purity consists in enclosing the flour in a muslin bag and squeezing it with the fingers while submerged in clean water, by which process the starch passes out in a state of white powder and subsides. Two essential constituents of flour are thus separated from each other; a viscid substance remains in the bag, which is called gluten, and the white powder deposited is starch.