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.