Punctuation / A Primer of Information about the Marks of Punctuation and their Use Both Grammatically and Typographically

by Frederick W. Hamilton

The comma may be omitted when the words are combined into a single idea.

A still hot day.

An old black coat.

2. After each pair in a series of pairs of words or phrases not connected by conjunctions.

Sink or swim, live or die, survive or perish,

I give my hand and my heart to this vote.

Formerly the master printer, his journeymen,

even his apprentices, all lived in the same house.

3. To separate contrasted words.