Bioelements; the Chemical Elements of Living Matter

Among the 87 known elements less than one-half (namely 34) have been found to enter into living matter. Of these only 17 seem to be essential to life, and of these 17 not more than 4 elements form from 97 to 99 per cent of the living organism. In order to illustrate the importance of the different elements Fig. 1 and Tables I and II have been prepared, showing that some elements occur invariably, others frequently, and still others are of such rare occurrence that their presence in living matter seems adventitious. In Fig. 1 the new periodic system 1 has been utilized to show that all the bioelements occupy neighboring places and that the majority of them possess low atomic weights, belonging to the first two periods of the system. An approximation to the ultimate composition of man is given in Column 2 of Table I, while Column 3 shows the elementary composition of long leaf pine, calculated from the data of Little? The chemical character of the mammal in comparison with the gymnosperm is evident, the latter containing 99 per cent of C, H, and O and only very small amounts of other elements, of which A1 and Si are the predominant ones (due to the abundance of these two elements in the soil). With the exception of oxygen, no element enters into the living organism as a free element, but only in the form of compounds, the majority of these being non-polar; that is, organic compounds. For