§ 799. Copper in the Vegetable and Animal Kingdom and in Foods.—Copper is widely distributed in the vegetable kingdom, and is a constant constituent of the chief foods we consume; the following quantities, for example, have been separated from the chief cereals:—
| Wheat, | 5 | ·2 | to 10·8 mgrms. | per kilo. | |
| Rye, | 5 | mgrms. | „ | ||
| Oats, | 8 | ·5 | mg„ | „ | |
| Barley, | 11 | ·8 | mg„ | „ | |
| Rice, | 1 | ·6 | mg„ | „ | |
| Bread, | 1 | ·5 | to 4·4 mgrms. | „ | |
It has also been found in vermicelli (2-10 mgrms. per kilo.), groats (1·6-3 mgrms. per kilo.), potatoes (1·8 mgrm. per kilo.), beans (2-11 mgrms. per kilo.). In similar small quantities it has also been found in carrots, chicory, spinach, hazel-nuts, blackberries, peaches, pears, figs, plums, tamarinds, black pepper, and many other fruits and spices. The most common food which has a high copper content is cocoa, which contains from 12 mgrms. to 29 mgrms. per kilo., the highest amount of copper being in the outer husk; copper has also been found in many supplies of drinking water, in aërated waters, in brandies, wines, and many drugs.
It has been calculated that the ordinary daily food of an average man contains the following:—
| Copper. | ||
|---|---|---|
| 900 grms. bread, | 0·45 | mgrm. |
| 260 grms. meat, | 0·25 | „ |
| 200 grms. fruit and vegetables, | 0·25 | „ |
| 0·95 | mgrm. | |
That is to say, that, neglecting altogether foods artificially contaminated with copper, each of us eats daily about 1 mgrm. of copper (0·015 grain).
In the animal kingdom it is a constant and natural constituent of the blood of the cephalopods, crustacea, and gasteropods, and is nearly always present in the liver and kidneys of domestic animals, as well as in men. Dr. Dupré[860] found ·035 to ·029 grain (1·8 to 2 mgrms.) in human livers, or about 1 part in 500,000. Bergeron and L. L’Hôte’s researches on fourteen bodies, specially examined for copper, fully substantiate those of Dr. Dupré; in twelve the copper was found in quantities of from ·7 to 1·5 mgrm.; in the remaining two the amount of copper was very minute, and was not estimated.[861] Copper is also found normally in the kidneys, and Dupré [862] detected in human kidneys about 1 in 100,000 parts; it is also found in the bile, and in minute traces in the blood.[863]
[860] Analyst, No. 13, 1877.
[861] Compt. Rendus, vol. lxxx. p. 268.