All 4 Uses of

molecule
in
Ulysses, by James Joyce

Molecules all change.†
Chpt 9 *

molecules = chemical substance comprised of the smallest amount of a chemical substance that can exist by itself

—As we, or mother Dana, weave and unweave our bodies, Stephen said, from day to day, their molecules shuttled to and fro, so does the artist weave and unweave his image.†
Chpt 9

Of the eons of geological periods recorded in the stratifications of the earth: of the myriad minute entomological organic existences concealed in cavities of the earth, beneath removable stones, in hives and mounds, of microbes, germs, bacteria, bacilli, spermatozoa: of the incalculable trillions of billions of millions of imperceptible molecules contained by cohesion of molecular affinity in a single pinhead: of the universe of human serum constellated with red and white bodies, themselves universes of void space constellated with other bodies, each, in continuity, its universe of divisible component bodies of which each was again divisible in divisions of redivisible component bodies, div†
Chpt 17

Of the eons of geological periods recorded in the stratifications of the earth: of the myriad minute entomological organic existences concealed in cavities of the earth, beneath removable stones, in hives and mounds, of microbes, germs, bacteria, bacilli, spermatozoa: of the incalculable trillions of billions of millions of imperceptible molecules contained by cohesion of molecular affinity in a single pinhead: of the universe of human serum constellated with red and white bodies, themselves universes of void space constellated with other bodies, each, in continuity, its universe of divisible component bodies of which each was again divisible in divisions of redivisible component bodies, div†
Chpt 17

molecular = relating to the smallest amount of a chemical substance that can exist by itself

Definitions:

(1) (molecule)
the smallest amount of a chemical substance that can exist by itself -- usually consisting of 2 or more atoms
(2) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

Less commonly, molecule is used informally to refer to anything that is very small.