FREE INSTITUTE OF SCIENCE PR 
STUDIES IN CARBOHYDRATES 
solution was ascertained by comparison, after three or four hours’ standing; 
when the last of the blue color could be recognized, a check was made with 
potassium ferrocyanid solution. The end point under these conditions cor- 
responded to 0.008 gm. of maltose for 2 c.c. of Fehling’s solution. 
Correction was made for the amount of moisture in the bread and the 
result expressed as per cent. 
EXPERIMENTS WITH STARCH 
Preliminary experiments were made with raw starch, starch cooked below 
and at the boiling temperature, starch as found in bread, crackers, peas, beans, 
and lentils. In each case microscopic examination was made. Experiments 
were also made to determine the gelatinization points of some starches. 
т. Raw SrARCH.—In this experiment potato, sago, sweet potato, tapioca, 
wheat, buckwheat, oat, rice, barley, pea, and bean starches were studied under 
the microscope, with and without polarized light and selenite plates, and with 
water, chloral hydrate, and glycerol as mounting media. (See Table 1.) 
TABLE 1.—EXAMINATION OF RAW STARCHES IN WATER, CHLORAL SOLUTION 
OR GLYCEROL. 
| | With POLARIZER 
SOURCE | Hırum RINGS Form a nacre 
| | Without Selenite With Selenite 
| 
Поко Es Central dot. Complete and | Ovate. | Crosses well | Colors brilliant. 
distinct. . | marked. 
Maramta Circle or line Complete and | Ovate. | Crosses well | Colors brilliant. 
often crack- | fairly distinct. | marked. 
ed. | ; 
SAO w KA Cerne Cleft or dot. Faint. Oval and trun- | Crosses well | Colors brilliant. 
cated. | marked. 
LAPIDO уз Central dot or | Invisible. Round or ket- | Crosses well Colors brilliant. 
cleft. tle drum. marked. 
Sweet potato...| Dot. Invisible. Round or bell- | Crosses well | Colors faint. 
shaped. marked. 
Come o А Dot cleit ‘or | Almost invisi- | Round or voly- | Crosses faint. | Colors faint. 
cross. ble: gonal. | 
Wheat........| Indistinct. | Indistinct. Round or oval. | Crosses faint. | Colors faint. 
Buckwheat.... Central dot or | Invisible. Polygonal, | Crosses well | Colors faint. 
cleft. | often com- marked. 
pound. | 
ШЕ АА l'aint. Faint. Polygonalanda Crosses very | Colors very 
few spherical. faint. faint. 
Rice enw Cleft or central | Invisible. Hexagonal, Cross well] Colors marked. 
dot. some triangu-| marked. 
lar. 
Barley. .. Cleft or central | Faint. Round or ov- Cross faint. Colors faint. 
dot. ate. 
Pea and bean. .| Furrow. Distinct. Oval or reni- Cross well} Colors marked. 
form. | marked. | 
