The person receiving the message knows the width of the column (four letters), the arrangement of the figures 1, 2, 3, and the use of the dots, and reconstructs his table directly; he then puts the letters in order by a backward process to the one we have gone through, and reads the message.

The next is a cipher of a different kind:--

O P | A B | C D .| . |.

-----+-----+----- | | M N .| Q R |. E F | . | -----+-----+----- .| . |.

K L | I J | G H

S T / / . / W X . >-< .="" u="" v="" .="" y="" z="">

The dots stand for the last letter in each square: thus O would be ___|, and P the same with a dot put in the middle, thus _._|. A |___| and B |_._|

The sentence, "ROUTLEDGE'S MAGAZINE FOR BOYS," would be

In finding out the meaning of a cryptograph, you must first settle in your mind to what cla.s.s of cipher it belongs, whether it is written by means of letters, figures, or signs; having done so, you must go to work with patience, and try to find out, by means of perseverance and study, what each figure, sign, or letter represents; as even the above specimens of cryptography can be so altered and improved upon, yet continuing in their original form to some extent, that it would be impossible to give positive rules to enable any one to decipher any kind of cryptograph; in fact, it can only be done by those who have made it their study for years, and consequently have had great experience in the matter.

Most of the examples given will only enable one to decipher the most simple kinds, such as are generally found in magazines, &c.; for if that intricate cipher of Lord Bacon's were put in a book for boys, it would be a waste of paper, as we will venture to say that not one in a thousand would be able to find it out.

There is another cla.s.s of cryptographs which we have not yet noticed, and which are done by means of sympathetic inks, a list of which will consequently be interesting.

_Inks which appear when heated, and become invisible when cooled_:--

Solution of nitro-muriate of cobalt; when heated turns green.

Solution of acetate of cobalt, with a little nitre; rose-colour when warm.

_Inks which remain visible when heated, but do not disappear when cooled_:--

Onion-juice, yellow; equal parts of copper and sal-ammoniac in water, yellow; aquafortis, spirits of salt, oil of vitriol, and salt and water, yellow or brown.

_Inks which appear when exposed to light_:--

Diluted solution of nitrate of silver.

Diluted solution of terchloride of gold.

[Ill.u.s.tration: PETER POUNCE, THE FIRST TEACHER OF THE DEAF AND DUMB, INSTRUCTING A BOY.]

THE DEAF AND DUMB ALPHABET.

Amongst the many useful inventions which have been planned for the solace of individuals deprived of some portion of their senses, the art by which deaf and dumb persons are taught to express their own thoughts, and to comprehend those of others, is one of the most n.o.ble. The earliest attempt at a method of teaching the deaf and dumb was made in Spain, towards the end of the sixteenth century, by a Benedictine monk named Peter Pounce; and without doubt he must have formed his idea from observing the natural propensity of the dumb to supply the want of the organs of speech by making signs. After the essay of Peter Pounce many successful trials were made, and in 1692 John Conrad Amman, a Swiss physician, reduced the plans to a fixed method, or art, and published the scheme of it at Amstelod. The first asylum for the deaf and dumb in London was founded in the year 1792.

THE ALPHABET.

[Ill.u.s.tration: A]

[Ill.u.s.tration: B]

[Ill.u.s.tration: C]

A is expressed by touching the top of the thumb of the left hand with the forefinger of the right.

B. Join the forefinger and thumb of each hand, and place the backs of the forefinger nails together.

C. Bend the fingers and thumb of the left hand, so as to form three parts of a circle.

[Ill.u.s.tration: D]

[Ill.u.s.tration: E]

[Ill.u.s.tration: F]

[Ill.u.s.tration: G]

D. Bend the fingers and thumb of the right hand into a semicircle, and then join them to the forefinger of the left, which keep in a straight line.

E. Touch the top of the forefinger of the left hand with the forefinger of the right.

F. Place the forefinger of the right hand across the backs of the first and second fingers of the left.

G. Clench both hands, and put one fist upon the other.

[Ill.u.s.tration: H]

[Ill.u.s.tration: I]

[Ill.u.s.tration: J]

H. Pa.s.s the palm of the right hand across that of the left, sweeping it along to the tips of the fingers, as if brushing something off.

I. Touch the top of the second finger of the left hand with the forefinger of the right.

J. Clench the hands together, as directed for the letter G.