Arch.—Archibald.
Arg.—Argumento, by an argument drawn from such a law.
Arith.—Arithmetic.
Ark.—Arkansas.
A. R. R.—Anno regni regis, in the year of the reign of the king.
A. R. S. S.—Antiquariorum Regiæ Societatis Socius, Fellow of the Royal Society of Antiquaries.
Art.—Article.
A. S. or Assist. Sec.—Assistant Secretary.
A. S. A.—American Statistical Association.
A. S. S. U.—American Sunday-School Union.