Air, the first necessity of life, 7; motion, coolness, humidity, and freshness of, important features of ventilation, 7; the matter of drafts, 8-9, 123-124, 274, 277; securing fresh, through windows, 9-10; prevention of stagnation of, by air-fans, 10; action of different heating systems, 10; importance of coolness of, 10-11; securing proper degrees of dryness and humidity, 11-12; lighting systems and, 13; evils of tobacco smoke and of dust, 13; bacteria in, carried by dust particles, 13-14; benefits of sunlight, 14; wearing of clothing which admits, 14-15, 275; benefits of out-of-door, 18-20, 276; outdoor sleeping, 20-24, 104, 220, 276; deep breathing, 24-27. Air-baths, taking of, 15-16, 148. Air-fans, use of, 10. Alcohol, modern movement against, 3; poisons in, 65, 241; ill effects of, 67-68; resistance to infectious diseases weakened by, 68; social evil traceable to, 123; to be avoided in cases of overweight, 216; statistics of influence of, on longevity, 227-235; per capita consumption of, in various countries, 235-236; laboratory and clinical evidence relating to physiological effects of, 236 ff.; effect on brain and the nervous system, 237-239; influence on bodily resistance to disease, 239-240; effect on heart and circulation, 240-241; food value of, 241-242; effect on offspring, 243; attitude of National Council of Safety toward, 244; condemnation of, shown by restrictive and prohibitive measures of governments, 244; references on subject of, 244-249. Alkaline dentifrices, 86. Amusements. See Recreation. Andalusian fowl, illustration from, of action of hereditary traits, 307-313. Anglo-Saxon race, effects of indoor living upon, 147. Animal cells, apparent immortality of, 142-143. Apoplexy, death rates from, 284, 285. Appetite, misleading of, by delicacies of civilization, 151-152. Apples, food value of, 30, 177, 179. Arch supports for flat foot, 224, 225. Arteries, tobacco and diseases of the, 69, 263. Arthritis deformans, caused by focal infection, 82. Asparagus, food value of, 41, 175. Asthenic droop, cause of, 58. Athletes, effects of tobacco on, 68, 69, 257-259. Athletics, ideals in, 96; injuries from college, 96. Attention, control of, essential to securing equanimity, 115. Autointoxication, meaning of, 81; intestinal intoxication distinguished from, 81-82. Avocation, practise of an, 98. Bacteria, carried on dust particles, 13-14; part played by, in colds, 272. _See_ Germs. Balanced ration, classification of foods with view to a, 171, 175-183. Bananas, food value of, 30, 177; digestibility of, 49; a cheap source of starch and sugar, 131. Bank employés, unsuspected impairments among, 136-137. Basal metabolism of the body, ascertaining the, 196-197.