CRYPTOGRAPHY.

This word, being derived from the Greek, "cryptos," a secret, and "graphein," to write, almost explains itself.

Cryptographs are formed by a substitution of one letter for another throughout a sentence, or by using figures, signs, &c., in the place of letters. Cryptography as a science is supposed to enter largely into State diplomacy, secret correspondence being maintained by its means with the various State officials scattered over the globe. In the commercial world it is a fact that such correspondence is transmitted by telegraph with much saving of labour and money and with perfect secrecy, each correspondent possessing a key which enables him to translate into plain words and sentences the otherwise unintelligible jumble of signs. The "agony column" of the daily papers often contains specimens of cryptographic writing, most mysterious to the general reader, but plain to those for whom it is intended. It is, however, as a means of amusement that Cryptography here finds a place.

The first requisite is to provide ourselves with a key. The following will serve as an example:—

A.B.C.D.E.F.G.H.I.J.K.L.M.N.O.P.Q.R.S.T.U.V.W.X.Y.Z.
8.z.w.t.3.s.r.v.4.p.n.m.l.a.5.e.i.o.u.f.2.h.6.g.x.d.

Shakspere's "Seven Ages" will then read thus:—

8mm fv3 65omtu 8 uf8r3,

8at 8mm fv3 l3a 8at 65l3a l3o3mx em8x3ou.

fv3x v8h3 fv34o 3g4fu 8at fv34o 3afo8aw3u,

8at 5a3 l8a 4a v4u f4l3 em8xu l8ax e8ofu,