with 13 of the 70 elements, namely: oxygen, hydrogen, nitrogen, chlorine, fluorine, carbon, phosphorus, sulphur, calcium, potassium, sodium, magnesium, and iron. Besides these, a few of the other elements, as silicon, have been found; but they exist in extremely minute quantities.
The following table gives the proportion in which these various elements are present:
Oxygen
62.430
per cent
Carbon
21.150
" "
Hydrogen
9.865
" "
Nitrogen
