lauses which are not
joined by a conjunction.= (For a possible exception see 91b.).

Wrong: He was alarmed in fact he was terrified.

Right: He was alarmed; in fact he was terrified.

Right: He drew up at the curb; he leaped from the car.

Note.--Very often the writer may choose freely between the semicolon and
the period; in such instances the use of the semicolon implies greater
logical unity between the clauses than the use of the period would show.
Unless this logical unity is distinct, the period is to be preferred.

=b. The semicolon is sometimes used between coordinate clauses which are
joined by a conjunction if the clauses are long, or if the clauses have
commas within themselves, or if obscurity would result were the
semicolon not used.= (Otherwise, see 91a.)

Right: Very slowly the glow in the heavens deepened and
extended itself along the eastern horizon; but at last the
bright-red rim of the sun showed above the crest of the hill.

Right: He arrived, so they tell me, after nightfall; and
immediately going to a hotel, called for a room.

Confusing: She enjoyed the dinners, and the dancing, and the
music, and the whole gay round of fashionable life was a
delight to her.

Better. She enjoyed the dinners, and the dancing, and the
music; and the whole gay round of fashionable life was a
delight to her.

=c. The semicolon is used between coordinate clauses which are joined by
a formal conjunctive adverb (_hence_, _thus_, _then_, _therefore_,
_accordingly_, _consequently_, _besides_, _still_, _nevertheless_, or
the like).=

Wrong: We have failed in this therefore let us try something
else.

Right: We have failed in this; therefore let us try something
else.

Wrong: He was tattered and muddy, besides he ate like a
cormorant.

Right: He was tattered and muddy; besides he ate like a
cormorant.

Note 1.--If a simple conjunction like _and_ is used in the sentences
above, a comma will suffice. But a comma is not sufficient before a
conjunctive adverb like _therefore_. Conjunctive adverbs may be clearly
distinguished from simple conjunctions (See 91a). They cannot always be
easily distinguished from subordinating conjunctions (see 90b, Note),
but the distinction, when it can be made with certainty, is an aid to
clear thinking.

Note 2.--Good usage sometimes permits a comma to be used before