When chemical tests show an excess of hydrochloric acid, salt should be omitted from the diet. A diet consisting largely of vegetables needs the addition of sodium chlorid to supply sufficient salt for body uses; likewise more salt than is contained in grass and fodder is needed for animals, particularly for those producing milk. The scientific farmer salts his cattle regularly, while wild animals travel miles and form beaten paths to springs containing salt. In rectal feeding, it is known that food absorbs more readily through the large intestine if salted. It is probable that salt, in normal proportions, also aids absorption in the stomach and small intestine. _Potassium_ is next in importance to sodium as it constitutes the chief salt in the muscles. It also aids the action of the digestive secretions and the maintenance of the reaction of the urine. Potatoes and apples are valuable foods on account of the potassium they contain. _Calcium_, if in excess, may cause the formation of calculi, renal or biliary. It is also found in the tartar which accumulates on the teeth, in the hardening walls of the arteries in arteriosclerosis, etc. All of the cabbage family are rich in calcium. Many mineral waters and the water from many wells contain it in excess. Those addicted to gall-stones, gravel, etc., should particularly avoid “hard” water. _Phosphorus_ and sulphur are obtained by the body from eggs and milk and from such vegetables as corn, cauliflower, asparagus, and turnips. _Iron_ is necessary in forming the pigment of the red blood corpuscles. If, through some disturbance in digestion, absorption or assimilation, the iron taken in the food is not utilized, or is insufficient in amount, the blood-making organs do not receive the necessary amount of this substance and the red corpuscles are not formed in sufficient numbers. The blood becomes poor in hemoglobin, and the individual becomes pale and loses vitality. This condition is known as anemia. FOOTNOTES: [2] For the process of digestion and the action of the digestive juices on the various food elements, see _Let’s Be Healthy_, by Susanna Cocroft. [3] PUBLISHER’S NOTE: The conversion in the body of starch and sugar into grape sugar, then into dextrose, then into glycogen, the glycogen being again broken up into grape sugar, is fully explained in Susanna Cocroft’s book _Let’s Be Healthy_. CHAPTER III CLASSIFICATION OF FOODS In the previous chapters, we have given the classification of the elements in foods (foodstuffs) which supply the body needs. In this chapter the foods commonly used are classified according to the predominance of these elements. _CARBONACEOUS FOODS_ While all foods contain a combination of elements, some contain a greater proportion of carbohydrates and fats, and are classed as _carbonaceous_. * * * * * [Sidenote: Roots and Tubers]