A text-book on chemistryFor the use of schools and colleges . 12^10^10 Cane Sugar (crystallized) O^H^O^ Grape Sugar Ol2Hl4:Ol4: Fruit Sugar Ol2H12Ol2 Milk Sugar Cl2H]2012 Gum Cl2HyiOn Lignine \C12HQ Oa Etc. Etc. Starch, Feculci, Amylum (C12IZ1O01O), is found abun-dantly in the vegetable kingdom, and may be obtainedfrom potatoes by rasping, and washing the mass upon asieve, the starch being carried off by the water. It mayalso be obtained from flour by making the flour intoa paste with water and then washing it. The starchseparates, and gluten is left behind. It is a white substance, commonly m
A text-book on chemistryFor the use of schools and colleges . 12^10^10 Cane Sugar (crystallized) O^H^O^ Grape Sugar Ol2Hl4:Ol4: Fruit Sugar Ol2H12Ol2 Milk Sugar Cl2H]2012 Gum Cl2HyiOn Lignine \C12HQ Oa Etc. Etc. Starch, Feculci, Amylum (C12IZ1O01O), is found abun-dantly in the vegetable kingdom, and may be obtainedfrom potatoes by rasping, and washing the mass upon asieve, the starch being carried off by the water. It mayalso be obtained from flour by making the flour intoa paste with water and then washing it. The starchseparates, and gluten is left behind. It is a white substance, commonly met with in irreg-ular prismatic masses, which shape it assumes whiledrying. It is almost insoluble in cold water, and en-tirely so in alcohol and ether. It consists of granulesof different sizes, as in Fig. 299, those of the potato be-ing about the two hundred and fiftieth of an inch in di-ameter. What is the peculiarity of the starch group? Name the membersof the starch group, and give their composition. Whence is starchobtained ? What are its properties ?. 392 STARCH. Fig. 299. When starch is heated in wa- ter, the covering membrane ofeach granule bursts open, andthe interior matter dissolves the proportion of starch beconsiderable, the whole forms ajelly-like mass, which may bedried into a yellowish body hav-ing the same constitution asstarch itself. Gelatinous starchpasses under the name of Amidine. With free iodine starch strikes a deep blue water containing this compound is heated to212° the color totally disappears, and is not restoredon cooling; but if the source of heat be removed assoon as the color disappears, and when the temperatureis not much above 160°, the color returns. Starch andiodine constitute an exceedingly delicate test for eachother. Paper impregnated w^ith starch and iodide ofpotassium is blued by chlorine and bromine, and is use-ful as a test for ozone. In commerce, starch is found under various modifica-tions, such as Arrow-root, T
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Keywords: ., bookcentury1800, bookde, booksubjectchemistry, booksubjectphysics
