6 ORGANIC AND INORGANIC CHEMICALS GENERALLY-NAMELY, SUCH INORGANIC CHEMICALS AS CHEMICAL ELEMENTS, SALTS, ACIDS, BASES, HYDROXIDES, OXIDES, SULPHIDES, CARBIDES, SILICIDES, AND AZIDES; AND SUCH ORGANIC CHEMICALS AS ALIPHATIC COMPOUNDS, ALICYCLIC COMPOUNDS, AROMATIC COMPOUNDS AND HETEROCYCLIC COMPOUNDS