We know that the same elements, with practically the same chemical compositions may be wholesome food in one case and virulent poison in another. The protein of nuts and nitric acid both owe their distinctive characteristics to the nitrogen they contain. Sugar and alcohol not only contain the same elements, but represent very nearly the same chemical combinations. One is a good food, the other a strong poison. They taste and smell unlike and when consumed do not produce the same effects.

The air is rich in nitrogen. Plants are able to absorb it and assimilate it--to make proteins out of it. But animals cannot. We must get our nitrogen from foods.

It was pointed out in a previous chapter that the body it unable to manufacture vitamins and the essential amino-acids. It is capable of manufacturing sugars out of more than one kind of organic substance, but cannot produce this from crude carbon. Only in organic combinations are minerals usable. Only plants--vegetables and fruits--with the aid of sunshine, are capable of taking the crude mineral elements of the soil and organizing them.

Salts built up by plants, we shall call organic salts and those built up by other processes we shall call inorganic. The chemist may continue to declare that he can find no difference in the two groups of materials, but the animal body continues to make a distinction and to draw a sharp line of demarcation between the salts the chemist turns out and those turned out by the plant.

Iron is an essential element of the body. It is especially found in the red blood cells. We get it from fruits and vegetables. As we there find it, it is usable. But we cannot supply our bodies with iron by eating saw fillings or pig-iron. Its frequent use in drug form upsets digestion, producing headache, gastric distress and constipation.

Elements are available only in certain forms. We must draw our minerals from foods. In like manner must we draw our vitamins from foods. Synthetic vitamins are as useless as earth salts before these have been organized by the plant.

McCann truly says: "We must not assume because the chemist has calculated the iron of the red blood corpuscles as 'iron oxide' that it would be a good thing, therefore, to go to a drug store and purchase a dose of iron oxide. The iron in the blood does not exist in such form. The chemist has to reduce it to such form before he can recover it from the organic compounds in which it is found in life.

"Herein lies the great error made by the patent medicine manufacturer (also by the ethical practitioner. Author), who tries to make the people believe that because certain salts are found in the human body therefore medicines containing them are good for the human body.

'To assume that because 'calcium oxide' appears in an analysis of the blood serum it must therefore appear in the blood serum itself as calcium oxide is a childish error.

"The calcium, iron and other mineral salts as they appear in the blood and internal secretions are present in such wonderfully complex forms that they cannot be reproduced in the drug store or laboratory."

Otto Carque says: "In natural foods iron is found solely in the form of complicated iron compounds which have been built up by the life processes of plants. From these compounds hemoglobin is produced in the animal organism, which is not able to construct the highly complex organic molecule from inorganic substances." He points out that foods are organic wholes, "in which the tissue salts are chemically associated with the organic substances, and only in this form are they able to sustain vital force."

Experiments on anemic rats with diets containing drug iron, food ash containing iron, flour to which copper was added, etc., showed that by no kind of trick or makeshift diet could the anemia be overcome. The rats had to have real foods from nature's own food laboratory--the plant kingdom--in order to recover.

Thousands of invalids, feeble children, chlorotic girls and anemic patients are taking iron daily, often by injections, in drug preparations, and upon the prescription of a doctor. This is supposed to supply any deficiency in this element and give them health and strength. The practice is a snare and a delusion. It sometimes induces a facetious simulation of health, and deceives both the physician and his patient. But it has long been known that such iron is not assimilated by the body, while, when given to chlorotic individuals of the tubercular diathesis, it hastens the development of tuberculosis.

Phosphorus is a necessary constituent of the bones and nerves. But we must supply it to the body as we find it in plants. Crude rock phosphorus as it comes from the earth, is a powerful poison. Laws now prohibit its use in the manufacture of matches, because of its poisonous character. It particularly affects the jaw bone producing a condition known as "Fossy jaw." Its continued use, as a medicine, even in small doses, produces anemia and emaciation. Although so vitally essential to bone and nerve, phosphorus, when not. "organized," as we find it in plants, is the most virulent poison of any of the normal elements of the human body. A man of average size contains, normally, about two pounds of phosphorus, but two grains of this "disorganized" (this may be done by calcination of a bone), given to a healthy man, produces great excitement, particularly of the brain. Delirium, inflammation and death may be the result in a single hour. Ten times this amount, taken as nature gives it to us in food, produces no such trouble.

Phosphorus poisoning is characterized by nervous and mental symptoms, jaundice, vomiting, general fatty degeneration, the presence of bile pigments, albumen and other abnormal constituents in the urine, followed by death.

Chronic phosphorus poisoning was quite common among workers in match-factories. Necrosis of the jaw bone was one of its frequent results. It ranks with mercury in its power to wreck the bones.

It is claimed that animals and children are able to utilize inorganic phosphorus in building up their bones. Hens seem able to use inorganic phosphorus in making egg shells. But when we come to the question: Is the animal organism capable of building up organic phosphorus compounds out of inorganic phosphorus?--we are face to face with a different and vital problem.

Berg says "here most physiologists make the mistake of failing to distinguish between salt-like or ester-like compounds (the so-called mixed-organic compounds) and compounds into which the phosphorus has entered as a constituent part of an organic complex. Yet the chemical distinction is vital." "So far as the more highly organized animals, at any rate, are concerned, we do not know a single instance of such genuine reduction of phosphorus and the incompetence of the animal organism to achieve this reduction is the probable explanation of the inability of the higher animals to synthesize carbon chains." "Innumerable investigators have studied the problem, and almost all of them have come to the conclusion that no such synthesis can be effected within the animal body."