The Commercial Products of the Vegetable Kingdom / Considered in Their Various Uses to Man and in Their Relation to the Arts and Manufactures; Forming a Practical Treatise & Handbook of Reference for the Colonist, Manufacturer, Merchant, and Consumer, on the Cultivation, Preparation for Shipment, and Commercial Value, &c. of the Various Substances Obtained From Trees and Plants, Entering into the Husbandry of Tropical and Sub-tropical Regions, &c.

by P. L. Simmonds

TABLE NO. IV.—SHOWING THE ORDER OF CLEARNESS OR TRANSLUCENCY OFUNIFORMLY 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.