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