The starches have been classified by Dr. Muter, according to the
appearance they give under the microscope, into five groups:
_Class I_.--Hilum and concentric rings visible. All the granules, oval
or ovate. Tous-le-mois, potato, arrowroot, etc.
_Class II_.--The concentric rings are all but invisible, the hilum is
stellate. Maize, pea, bean, etc.
_Class III_.--The concentric rings are all but invisible, also the hilum
in the majority of granules. Wheat, barley, rye, chestnut, etc.
_Class IV_.--All the granules truncated at one end. Sago, tapioca, etc.
_Class V_.--All the granules angular in form. Rice, tacca, arrowroot,
oats, etc.
The principal starches used for finishing cotton fabrics are potato
(farina), wheat, Indian corn (maize), rice, tapioca, arrowroot, sago;
the last three not so often as those previously named.
[Illustration: POTATO STARCH.]
[Illustration: ARROWROOT STARCH.]
[Illustration: WHEAT STARCH]
[Illustration: RICE STARCH]
[Illustration: SAGO STARCH]
[Illustration: INDIAN CORN STARCH]
[Illustration: TAPIOCA STARCH]
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