Argillite, of the Connecticut valley, account of, vi, 35.

Aristotle, notice of, C. Fox, xxxvi, 217.

Armature, see [Electro-magnet], and [Magnet].

Arragonite, analysis of, M. Stromeyer, vii, 368.

—, in Canada, viii, 70.

—, in New York, xxi, 326; xxviii, 172.f

—, of New Jersey, J. Finch, xviii, 197.

Arragonite and calc spar, Becquerel, xxiii, 387.

[Arsenic,] on the detection of, L. Feuchtwanger, xix, 339.f

—, application of Riench's test, D. P. Gardner, xliv, 240.