simple classification of, III 621 based on principal nutritive substances, III 624 purposes of different classes of, III 625 difference between digestibility and assimilability of, III 630 table showing comparative assimilability carbohydrate and water content of various classes of food, III 632 purpose of the vieno table in, III 634 vieno system of, III 645 values, measurement of, III 639 values, measurement of--(old system), III 642 amount of nitrogen in, incorrect standards, III 645 incorrect standards of measurement of, III 646 what constitutes a true, III 647 explanation of vieno system of food measurement, III 648 edible portion of, III 650 how to reduce foods to vienos, III 651 nitrogen factor in, III 651 direct method of calculating available nitrogen in, III 655, III 663 curative value of, III 668 for children (see menus for children), III 687 in cirrhosis of the liver, III 823 in consumption, IV 989-990 in pregnancy, IV 1033 selection, combination and proportion of, V 1149, V 1152 according to age, V 1149 according to time of year, V 1151 according to work or activity, V 1151 and energy, V 1310 relative importance of air, water and, V 1313 FORMALDEHYDE uses of, I 93 an artificial preservative, I 93 a poison to the human system, I 93 FOWL selection of, III 678 preparation of, III 678