Element Arsenic, As, Metalloid. In accordance with its smaller combining weight, arsenic. Deviates still more than antimony from the type of the metals, and exhibits greater similarity to the non-metal phosphorus; at the same time the tendency to form acid compounds increases. In fact the resemblance of arsenic to phosphorus is so great that it might also have been treated along with that element among the non-metals. If the vapour of arsenic. At the same time, other kinds of amorphous arsenic are formed.

Element Boron, B, Metalloid. Among the non-metallic elements, boron. Containing carbon, and obtained from the two elements at a very high temperature, is of a similar character, and also possesses an adamantine hardness. This also ought most probably to be regarded as a solid solution, and not as a chemical compound. The combining weight of boron is B. Have been known of for thousands of years. Century a substance was disengaged from burah. Which was called boronic acid. And Davy called it boron.

Element Carbon, C, Non Metal. Sugar charcoal is much purer than wood charcoal, because in it the presence can easily be avoided of non-volatile impurities which are present in the case of wood charcoal, and which, on complete combustion, remain behind as a grey powder, the ash. The properties of this form of carbon are the well-known black colour, a small density, easy combustibility, small conductivity for heat and electricity, and a low degree of hardness. From ancient times are amorphous carbon.

Element Germanium, Ge, Metalloid. Matched those of the eka-silicon whose existence had been predicted in 1871 by Dmitri Mendeleev. By mass, more than that of Antimony, Silver and Bismuth.

Element Nitrogen, N, Non Metal. There is present in the air, besides oxygen, another substance which constitutes the greater part both by weight and by volume. From the fact that the residue of the air after removal of the oxygen can support neither combustion nor life, it was called azote, but it is now called nitrogen. Its chemical symbol is N. Its combining weight is N. Is in so far of especia.

Element Phosphorus, P, Non Metal. The name phosphorescence, used in physics for the after luminescence shown by certain substances after a previous exposure to light, is a relic of that usage. At the present day, the name phosphorus. The nerve and brain substances, more especially, are comparatively rich in phosphorus, which is there .

Element Aluminium, Al, Poor Metal. Of all the light metals, aluminium. It forms a constituent of almost all crystalline silicate rocks; and of the secondary formations, the clays and slate formations are formed from aluminium silicate. A knowledge of the compounds of this metal, therefore, extends back as far as chemical knowledge at all can be traced. While, even at comparatively high temperatures, massive aluminium is only superficially and inappre.