It seems doubtful whether "_its_ quality" is the _adjective's_ quality, or the _substantive's_; but in either sense, the phrase is false; for an adjective is added to a noun, not to express any quality either of the adjective or of the noun, but to express some quality of the _thing signified_ by the noun.

But the definition is too much restricted; for adjectives may be added to pronouns as well as to nouns, nor do they always express _quality_.
24.

FOURTH DEFINITION:--"A Pronoun is a word used instead of a noun, to _avoid the too frequent_ repetition of _the same word_."-- _Dr.Ash's Gram._, p.

25; _Murray's_, 28 and 50; _Felton's_, 18; _Alger's_, 13; _Bacon's_, 10; _and others_.

The latter part of this sentence is needless, and also contains several errors.1.The verb _avoid_ is certainly very ill-chosen; because it implies intelligent agency, and not that which is merely instrumental.2.The article _the_ is misemployed for _a_; for, "_the_ too frequent repetition," should mean _some particular_ too frequent repetition--an idea not intended here, and in itself not far from absurdity.3.The phrase, "_the same word_" may apply to the pronoun itself as well as to the noun: in saying, "_I_ came, _I_ saw, _I_ conquered," there is as frequent a repetition of _the same word_, as in saying, "_Caesar_ came, _Caesar_ saw, _Caesar_ conquered." If, therefore, the latter part of this definition must be retained, the whole should be written thus: "A Pronoun is a word used _in stead_ of a noun, to _prevent_ too frequent _a_ repetition of _it_." 25.