Nervous troubles, outdoor treatment for, 21.

Neurasthenia, sometimes caused by a slouching posture, 57.

New York City, expectation of life in, compared with England and Wales,
and London, 289.

New York State, death rate statistics of, 287, 288.

Nicotin, percentage of, in tobacco, 251-254;
amount of, in tobacco smoke, 254-255, 260-261;
effects of, 255-256;
experiments with, on animals, 263.

Night air, mistaken ideas concerning, 22.

Nose, cleaning the, 70, 276-277.

Nuts, vitamins supplied by, 42;
among the best foods, 48;
digestibility of, when properly chewed, 49;
table of food values of, 183.

Oatmeal, food value of, 29, 180.

Obstacles, to hygiene, 126-135.

Oils, as laxative food, 52;
as intestinal lubricants, 53.

Oleomargarine, a cheap source of fat, 131.

Olive oil, a concentrated food, 28-29.

Olives, food value of, 30, 182.

Onions, cellulose in, 41;
food value of, 176.

Oranges, food value of, 30, 177.

Outdoor living, benefits, of, 18-20, 276.

Outdoor schools, 19.

Outdoor sleeping, 20-24, 104.

Overeating, causes of, 154;
nasal congestion from, 276.

Overheating of rooms, 11.

Overnourishment, from too free use of sugar, 48.

Overstrain, results of, 90;
prevention of, 91-92.

Overweight, influence of, on longevity, 30-31;
life insurance estimates as to, 31-32, 213;
determination of, 31;
importance of checking tendency to, 32;
eating-habits that cause, 32-33;
diet for, 215-216;
fats to avoid, 216;
exercise for, 217;
main reliance to be placed on dietetic regulation rather than on
exercise, 217;
avoidance of sudden reduction in weight, 217-218;
reduction of weight a simple matter, 218-219.

Overwork, popular delusions concerning, 124-125.

Pack, Fred. J., statistics by, on effects of tobacco, 256-259.

Paraffin oil, an intestinal lubricant, 53.

Parsnips, food value of, 41, 176.

Pasteurization, milk left uncooked by, 42-43.

Pastry, table of food values of, 179.

Patent medicines, habit-forming drugs in, 65.

Peanuts, food value of, 30, 183;
digestibility of, 49;
a cheap source of protein, 131.

Peas, a high-protein food, 38;
protein in, a possible objection, 39-40.

Pecans, food value of, 30, 183.

Pepper, to be used sparingly, 48.

Peroxide of hydrogen, for