Manual of practical medical and physiological chemistry / by Charles E. Pellew.

  • Pellew, Charles E. (Charles Ernest), Viscount Exmouth, 1863-1945.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Manual of practical medical and physiological chemistry / by Charles E. Pellew. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    Many of them crystallize readily, like cane and milk sugar and dextrose; others can be crystallized, but only with great diflfi- culty. Still others of the series, like starch and cellulose, are distinctly colloid in both appearance and properties. These latter are of a more complex structure than the former. Their exact chemical composition is at present but little known. Classification.—Carbohydrates can be classified according to their composition, dividing them with reference to the number of times that they contain a group of six carbon atoms. On this basis the following table can be made : I. MOXO-SACCHARIDS, or GtLUCOSES.—CeHriOe. Dextro-gluGose (dextrose, grape sugar). Zcevo-glucose (Isevulose). Galactose. /Sorbose, and others, of less importance. II. Di-Saccharids, or Saccharoses.—Ci^HoaOii. Sucrose (saccharose, cane sugar). Lactose (milk sugar). Maltose (malt sugar) and others. III. POLT-SACCHARIDS.—u(C6Hio05) ± mCHsO). 1st. Crystallizing. Rafflnose, lactosin, and others, all of little iniportance. 2d. Colloid. Cellulose. Starch, dextrins, and other derivatives, all polarizing to the right. Inulin, and its derivatives, polarizing to the left. Glycogen. Arabinose, gums, etc. In general it may be said that the last group, of poly-saccharids, is by far the most complex in character. Its members may be readily broken down into simpler carbohydrates by a variety of reagents, while, so far, with but few exceptions, we have been unable to build them up without the agency of plant life. The second group, of di-saecharids, although simi)]er than the last, and in some cases made from them, are still far more