Lindley Murray gives the following judicious directions in regard to the
use of capital letters:—
It was formerly the custom to begin every noun with a capital; but as
this practice was troublesome, and gave the writing or printing a crowded
and confused appearance, it has been discontinued. It is, however, very
proper to begin with a capital,—
1. The first word of every book, chapter, letter, note, or any other
piece of writing; and,
2. The first word after a period; and, if the two sentences are _totally
independent_, after a note of interrogation or exclamation. But if a
number of interrogative or exclamatory sentences are thrown into one
general group, or if the construction of the latter sentences depends
on the former, all of them, except the first, may begin with a small
letter: as, _How long, ye simple ones, will ye love simplicity? and the
scorners delight in their scorning? and fools hate knowledge?_—_Alas! how
different! yet how like the same!_
3. The appellations of the Deity: as, _God_, _Jehovah_, _the Almighty_,
_the Supreme Being_, _the Lord_, _Providence_, _the Messiah_, _the Holy
Spirit_.
4. Proper names of persons, places, streets, mountains, rivers, ships:
as, _George_, _London_, _the Strand_, _the Alps_, _the Thames_, _the
Seahorse_.
5. Adjectives derived from the proper names of places: as, _Grecian_,
_Roman_, _English_, _French_, _Italian_.
6. The first word of a quotation, introduced after a colon, or when it
is in a direct form: as, _Always remember this ancient maxim: “Know
thyself.”_—_Our great Lawgiver says, “Take up thy cross daily, and follow
me.”_ But when a quotation is brought in obliquely after a comma, a
capital letter is unnecessary: as, _Solomon observes, “that pride goes
before destruction.”_
The first word of an example may also very properly begin with a capital:
as, _Temptation proves our virtue_.
7. Every substantive and principal word in the titles of books: as,
_Johnson’s Dictionary of the English Language_; _Thomson’s Seasons_;
_Rollin’s Ancient History_.