_Detection of Saccharin._[25]--Add from 25 to 40 c.c. of water to about 20 grams of the sample; macerate and strain through muslin; acidify with 2 c.c. of sulfuric acid (1 to 3) and extract with ether. Separate the ether layer, allow the ether to evaporate spontaneously, and take up the residue with water. If saccharin be present its presence will be indicated by the sweet taste imparted to the water. To confirm this test add from one to two grams of sodium hydroxid, and place the dish in an oil bath. Maintain the temperature of the oil at 250° C. for 20 minutes, when the saccharin will be converted into salicylic acid. After cooling and acidifying with sulfuric acid, extract in the usual way and test for salicylic acid. This test, of course, presupposes the absence of salicylic acid in the original sample. If salicylic acid is present in the original sample it must be removed before making the test for saccharin. [25] _Ibid._, Bul. 65, p. 51. [Illustration: FIG. 27.--INDIAN CORN STARCH. × 200.--(_Bureau of Chemistry._)] =Starch of Indian Corn.=--Maize starch has characteristics which enable it to be easily detected by the microscope. The granules of this starch are of a more uniform size than those of wheat and vary from 20 to 30 microns in diameter. Occasionally very much smaller granules occur which probably are more of the original size and which have been arrested in growth by the ripening of the grain. The granules of maize starch are more or less polyhedral in form with round angles. The only common cereal starch which they can be mistaken for is rice, but they are generally larger than the granules of rice. Under the microscope with ordinary light they give only the faintest sign of rings but show in most cases a well developed hilum, which is at times star-shaped or like an irregular cross, while at other times it has the appearance of a circular depression. The maize starch granular is a type of the angular, as the wheat is of the sphere or spheroid form. The characteristic appearance of maize starch kernels is shown in the accompanying Fig. 27. Viewed with polarized light the starch grains of Indian corn present deep, well marked crosses, which divide each grain into four distinct parts as shown in Fig. 28. It is interesting to note that the angularity of maize starch is greatly influenced by the hardness of the kernels from which the grains are taken. The hard varieties, such as popcorn, have very angular grains while those from soft varieties have a great many almost spherical forms. [Illustration: FIG. 28.--STARCH GRAINS OF INDIAN CORN, UNDER POLARIZED LIGHT. × 200.--(_Courtesy of Bureau of Chemistry._)]