Found in this volume are practical hints in regard to food and the usefulness or harmful effects of the various articles of diet. Many of the subjects here discussed have previously been but little or hardly at all touched upon in scientific works, as, in example, the manner in which various functions such as the intelligence, the sexual function, etc. can be activated through the diet. Contents: Influence of food upon man; Fundamental laws of rational feeding; Injurious modes of feeding; Good & evil effects of various food substances; Vegetarianism & its advantages & disadvantages. Hints for the prevention of the latter; Practical advantages of rational feeding; Hints for those obliged to take their meals in restaurants; Increased activity of certain functions brought about by food; Increased muscular power resulting from a suitable diet; Relationship of food to old age & longevity.