OLD AGE. This needs no definition. Sometimes old age is the cause of loss of memory and of the powers of the mind, when the party may be found non compos mentis. See Aged¹ witness; Senility.

OLD NATURA BREVIUM. The title of an old English book, (usually cited Vet². N. B.) so called to distinguish it from the F. N. B. It contains the writs³ most in use in the reign⁴ of Edward III, together with a short comment on the application and properties of each of them,

OLD TENURES. The title of a small tract⁵, which, as its title denotes, contains an account of the various tenures by which land was holden in the reign of Edward III. This tract was published in 1719, with notes and additions, with the eleventh edition of the First Institutes, and reprinted in 8vo. in 1764, by Serjeant Hawkins, in a Selection of Coke's Law Tracts⁶.

OLERON LAWS. The name of a maritime⁷ code. Vide Laws of Oleron.

OLIGARCHY⁸. This name is given to designate the power which a few citizens of a state have usurped⁹, which ought by the constitution to reside in the people. Among the Romans the government degenerated¹⁰ several times into an oligarchy; for example, under the decemvirs, when they became the only magistrates¹¹ in the commonwealth¹².

OLOGRAPH. When applied¹³ to wills or testaments¹⁵, this term signifies that they are wholly written by the testator himself. Vide Civil, Code of Louisiana, art. 1581: Code Civil, 970; 6 Toull. n. 357; 1 Stuart's (L. C.) R. 327; 2 Bouv. Inst. n. 2139; and see Testament¹⁴, Olographic; Will, Olographic.

OMISSION¹⁶. An omission is the neglect to perform what the law requires.

2. When a public law enjoins¹⁷ on certain officers duties to be performed by them for the public, and they omit to perform them, they may be indicted¹⁸: for example, supervisors¹⁹ of the highways are required to repair the public roads; the neglect to do so will render them liable to be indicted.

3. When a nuisance arises in consequence of an omission, it cannot be abated²⁰ if it be a private nuisance without giving notice, when such notice can be given. Vide Branches; Commission; Nuisance; Trees.

OMNIA PERFORMAVIT. A good plea in bar, where all the covenants²¹ are in the affirmative. 1 Greenl. R. 189.