5. Expired breath loaded with carbonic acid and watery vapor.
7. Motive force of simple alternate contraction and relaxation in the muscles, which, acting through joints, tendons, and levers, does work of endless variety.
8. A deficiency of food, drink, or air, first disturbs, then stops the motion and the life.
Carrying out this analogy, you will at once see why a person working hard with either body or mind requires more food than the one who does but little. The food taken into the human body can never be a simple element. We do not feed on plain, undiluted oxygen or nitrogen; and, while the composition of the human body includes really sixteen elements in all, oxygen is the only one used in its natural state. I give first the elements as they exist in a body weighing about one hundred and fifty-four pounds, this being the average weight of a full-grown man; and add a table, compiled from different sources, of the composition of the body as made up from these elements. Dry as such details may seem, they are the only key to a full understanding of the body, and the laws of the body, so far as the food-supply is concerned; though you will quickly find that the day's food means the day's thought and work, well or ill, and that in your hands is put a power mightier than you know,--the power to build up body, and through body the soul, into a strong and beautiful manhood and womanhood.
---------------------------------------------------------|------|-----|----- | Lbs. | Oz. | Grs. ---------------------------------------------------------|------|-----|----- 1. Oxygen, a gas, and supporter of combustion, | | | weighs | 103 | 2 | 335 | | | 2. Carbon, a solid; found most nearly pure in charcoal. | | | Carbon in the body combines with other | | | elements to produce carbonic-acid gas, and by | | | its burning sets heat free. Its weight is | 18 | 11 | 150 | | | 3. Hydrogen, a gas, is a part of all bone, blood, and | | | muscle, and weighs | 4 | 14 | 0 | | | 4. Nitrogen, a gas, is also part of all muscle, blood, | | | and bone; weighing | 4 | 14 | 0 | | | 5. Phosphorus, a solid, found in brain and bones, | | | weighs | 1 | 12 | 25 | | | 6. Sulphur, a solid, found in all parts of the body, | | | weighs | 0 | 8 | 0 | | | 7. Chlorine, a gas, found in all parts of the body, | | | weighs | 0 | 4 | 150 | | | 8. Fluorine, supposed to be a gas, is found with calcium | | | in teeth and bones, and weighs | 0 | 3 | 300 | | | 9. Silicon, a solid, found united with oxygen in the | | | hair, skin, bile, bones, blood, and saliva, weighs | 0 | 0 | 14 | | | 10. Magnesium, a metal found in union with phosphoric | | | acid in the bones | 0 | 2 | 250 | | | 11. Potassium, a metal, the basis of potash, is found | | | as phosphate and chloride; weighs | 0 | 3 | 340 | | | 12. Sodium, a metal, basis of soda; weighs | 0 | 3 | 217 | | | 13. Calcium, a metal, basis of lime, found chiefly in | | | bones and teeth; weighs | 3 | 13 | 190 | | | 14. Iron, a metal essential in the coloring of the | | | blood, and found everywhere in the body; | | | weighs | 0 | 0 | 65 | | | 15. Manganese. } Faint traces of both these metals | | | } | | | 16. Copper metals.} are found in brain and blood, | | | but in too minute portions to be given by | | | weight. | | | |------|-----|----- Total | 154 | 0 | 0