  The words “atom” and “atoms” will be often used in the following pages. Therefore, it is deemed proper to state the nature and properties of an atom, so far as known. It is defined as: “An extremely minute particle of matter; a hypothetical particle of matter, so minute as to admit of no division; an ultimate indivisible particle of matter. (Cent. Dic. 1, p. 365.) The Encyclopedia Britannica says: “Atom is a body which cannot be cut in two. The Atomic theory is a theory of the constitution of bodies, which asserts that they are made up of atoms.” (Encyc. Brit. 3, p. 36.) A molecule is the smallest mass of any substance, which is capable of existing in a separate form; that is the smallest part, into which the substance can be divided without destroying its chemical identity. A molecule of any substance is conceived of as made up of two or more atoms. (Cent. Dic. 5, p. 3822.) In biology a cell is defined, first, as the fundamental form-element of every organized body. Secondly, as a nucleated, capsulated form element of any structure or tissue; one of the protoplasmic bodies, which build up an animal fabric; a body consisting of cell-substance, cell-wall and cell-nucleus, as bone-cell, etc. (Cent. Dic. 1, p. 878.) The body of every animal and plant is made of cells; and each cell is composed of many atoms. For a full discussion of “The Atomic Theory,” |
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