(mix). A heterogeneous association of substances that cannot be represented by a chemical formula. Its components may or may not be uniformly dispersed and can usually be separated by mechanical means. Liquids that are uniformly dispersed are called solutions. Mixtures may be natural or artificial, as indicated by the following: Natural Artificial air glass petroleum paint milk cement blood perfumes marble plastics wood cermets latex alloys vegetable oils seawaterSee Compound; Blend; solution; Mixing.