There is but little difficulty in ascertaining the chemistry of natural foods, but when they have been preserved, pickled, canned, smoked, evaporated, milled, roasted, toasted, oiled, boiled, baked, mixed, flavored, sweetened, salted, soured and put into the popular commercial forms, it becomes very difficult, if not impossible, to know what we are eating, or to estimate the results. Man is the net product of what he eats and drinks. Food bears very much the same relation to him that soil does to vegetation. The following questions, therefore, should be solved by every one who believes that success and happiness depend upon health and vitality: 1 How to select and how to combine foods which will give to the body a natural result, which is _health_ 2 How to select and how to combine foods so that they will counteract and remove the causes of dis-ease 3 How to select foods which contain all the chemical elements of the body, and how to combine and proportion them at each meal so that they will chemically harmonize 4 How to determine the quantity of food to be taken each day, or at each meal, that will give to the body all the nourishment it is capable of assimilating _Note_: Too much food, even of the right kind, defeats this purpose and produces just the opposite result. * * * * * Upon this knowledge hinges the building of a natural body, the cure of a vast majority of dis-eases, our ability to reach the highest state of physical and mental vitality, the prolongation of youth and longevity. OUR FOOD MUST FIT INTO OUR CIVILIZATION _We must make our diet fit into our civilized requirements._ Civilization has imposed many customs, habits, and duties upon us that have not been properly met by nutrition or diet. This is why nearly 91 per cent of our ills are caused by errors in eating. [Sidenote: Effect of sedative occupations upon nutrition] Under continued physical exertion, the body will thrive for a time on an unbalanced diet. It will cast off surplus nutrition, and convert one element into another, a problem unknown to modern science, but under sedative or modern business habits and occupations, it will not continue to cast off a surplus, or to reconvert nutritive elements. As a result of an unbalanced bill of fare, the nutrients taken in excess of the daily needs undergo a form of decomposition, producing what is called autointoxication, and become a most prolific source of dis-ease. WHY THE SCIENCE OF HUMAN NUTRITION IS IN ITS INFANCY The reader may inquire why it is that all other branches of science have advanced so rapidly, and the science of human nutrition has just begun. The reasons are: 1 Our ancestors, for many thousand years, were taught that dis-ease was a visitation of Divine Providence, therefore to combat it was to tempt the Almighty.