Composition of the Human Body.

Not only does food supply the daily waste of the human body, but, as the body increases in size from birth to adult age, it is supplied with materials for this increase by the aid of food. In order, therefore, to understand the value of food from its composition, it is necessary to know the composition of the human body. Just as any other compound substance can be submitted to chemical analysis and the elements of which it consists ascertained, so can the composition of the human body be discovered. Such analyses of course become difficult in proportion to the complication of the body analysed, and only an approach to the true quantities in which the elements exist can be expected. In Case No. 1, Division A., the results of such an analysis have been attempted, and the quantities of each element entering into the composition of a human body weighing 11 stone or 154 pounds are (as far as possible) presented to the eye.

The following are the elements and their quantities:—

Ultimate Elements of the Human Body.

lbs. ozs. grs.
1. Oxygen, a gas. The quantity contained in the body would occupy a space equal to 1,314 cubic feet 111 0 0
2. Carbon, a solid. When obtained from animals it is called animal charcoal 21 0 0
3. Hydrogen, a gas. The lightest body in nature. The quantity present would occupy about 2,622 cubic feet 14 0 0
4. Nitrogen, a gas. It would occupy, when free, about 46 cubic feet 3 9 0
5. Calcium, a solid. The metallic base of lime which has not yet been obtained in sufficient quantity to be employed in the arts. It is about the density of aluminium 2 0 0
6. Phosphorus, a solid. This substance is so inflammable that it can only be kept in water 1 12 190
7. Chlorine, a gas. When combined with sodium it forms common salt 0 2 382
8. Sulphur, a solid. A well-known substance. It unites with hydrogen, forming sulphuretted hydrogen, which gives the unpleasant smell to decomposing animal and vegetable matter 0 2 219
9. Sodium, a metal. It is so light that it floats on water, and is kept in naphtha to prevent its oxidation 0 2 116
10. Fluorine, a gas. This substance has not been separated in such a manner as to permit of an examination of its properties, and cannot be exhibited. It is found united with calcium in the bones 0 2 0
11. Potassium, a metal. Like sodium it floats on water, and burns with a flame when placed on it 0 0 290
12. Iron, a metal. In small quantities it is necessary to the health of the body 0 0 100
13. Magnesium, a metal. Combined with oxygen it forms magnesia 0 0 12
14. Silicon, a non-metallic substance. With oxygen it forms silex or silica. It enters into the composition of the teeth and hair 0 0 2
154 0 0

Other elements have been found in the body, as copper and manganese, but these are probably accidental.

These elements, when combined together, form a set of compound bodies called “proximate principles,” out of which the tissues and fluids of the body are formed.

Proximate Principles of the Human Body.

lbs. ozs. grs.
1. Water, composed of oxygen and hydrogen gases 111 0 0
2. Gelatin, of which the walls of the cells and many tissues of the body, as the skin and bones, are principally composed 15 6 0
3. Fat, which constitutes the adipose tissue 12 0 0
4. Phosphate of Lime, forming the principal part of the earthy matter of the bones 5 13 0
5. Fibrin, forming the muscles and the clot and globules of the blood 4 4 0
6. Albumen, found in the blood and nerves 4 3 0
7. Carbonate of Lime, also entering into the composition of bone 1 0 0
8. Chloride of Sodium, common salt 0 3 376
9. Fluoride of Calcium, found in the bones 0 3 0
10. Sulphate of Soda 0 1 170
11. Carbonate of Soda 0 1 72
12. Phosphate of Soda 0 0 400
13. Sulphate of Potash 0 0 400
14. Peroxide of Iron 0 0 150
15. Phosphate of Potash 0 0 100
16. Phosphate of Magnesia 0 0 75
17. Chloride of Potassium 0 0 10
18. Silica 0 0 3
154 0 0

These compounds, in passing away from the body, form many others, which may be here left out of consideration as not forming a necessary part of the fabric of the human body.