As in the case of nearly all deductive reasoning the handwriting expert becomes sensitive to slight suggestions. If called upon, as he sometimes is, to explain to others how and why one of these slight and almost imperceptible signs fit in with his theory, he fails. Therefore the cautious expert, like a good judge, is careful in giving reasons for his judgment only to cite those which are self-evident.

Many an expert has made a poor exhibition in the witness-box by failing to convey to a jury the impression produced on his own mind by a slight piece of evidence, the proper understanding and interpretation of which can only be grasped by those who have learned how to recognize faint signs.

The process of chemically testing inks for the purpose of ascertaining the points mentioned is quite simple, and is distinctly interesting. In a very important case the services of a qualified chemist will probably be requisitioned, but the cost of the necessary material and the time required to make oneself proficient as a capable tester are so slight that even the small fee that would be charged by a chemist is scarcely worth paying.

The materials necessary are a few test tubes, some bottles of lime water, diluted muriatic acid, a solution of nitrate of silver in distilled water, in the proportion of ten grains to the ounce, some camel hair pencils, and clean white blotting and litmus paper. The whole need not cost more than half-a-crown.

The method of using these materials is best ill.u.s.trated by describing a test often needed by autograph collectors.

A very common method employed by forgers to give an appearance of age to the ink used in spurious old doc.u.ments is to mix with ordinary ink, muriatic acid, oxalic acid, or binoxalate of potash. The presence of these colouring agents can be detected in the following manner.

In the first place, washing the letter with cold water will make the ink become darker if acid has been used to brown the ink, but the following test will settle the point beyond dispute:

With a camel's-hair brush wash the letter over with warm water. If, as sometimes happens, a sort of paint or coloured indian ink has been used, this will be immediately washed away and disappear, leaving a rusty smudge. If not, apply the litmus paper to the wetted ink, and the presence of acid will be shown in the usual way by the litmus paper changing colour. If genuine, wetting makes no difference.

Next, pour a drop or two of the water from the writing into a test tube from off the letter, add a little distilled water and one or two drops of the nitrate of silver solution.

If muriatic acid has been used to colour the ink, a thick white precipitate will be seen in the tube immediately.

If not, pour a few more drops of the water which has been washed over the writing into a second test tube, add a little distilled water and a few drops of lime water. A white precipitate will be seen in the tube if either oxalic acid or binoxalate of potash has been employed.

In many cases it will be sufficient to place the tip of the tongue to a thick stroke. An unmistakable acid taste will be noticed.

Further and fuller particulars of the methods resorted to by forgers to simulate ancient doc.u.ments will be given in the chapter on Autographs.

It is sometimes important to know whether a stroke has been made over another, as in the famous case in which the real issue turned on the question whether an apparent alteration in a signature was really a pen-mark made to indicate where the signatory should sign. It was obvious that if the mark was made first the signature would be over it; if, as was suggested, the mark was added in an attempt to alter or touch up the signature, it must have been written over the signature.

In cases of this kind an enlarged photograph leaves no room for doubt.

The ink is seen lying over the lower stroke as plainly as a layer of paint in a picture can be seen overlying the stroke beneath.

This is one of those apparently difficult points which become marvellously simple when dealt with in a practical manner.

Pages might be needed to explain what a very simple experiment will reveal at a glance.

Take a word which has been written long enough for the ink to have become dry, and make a stroke across it. For example, make a letter _t_ without the bar, then, after a lapse of an hour or two, add the cross bar. When this is quite dry and has become as dark as the first mark, examine it with a good gla.s.s. The ink of the added bar will be seen plainly overlaying the vertical stroke, but any doubt can be promptly removed by taking an enlarged photograph.

Even when the second stroke is added while the ink on the first is still wet the upper stroke can be distinguished, though not so clearly as if the first stroke had been allowed to dry first.

By practising and examining such strokes, the student will soon learn to distinguish important signs which leave no doubt as to which stroke was first made.

CHAPTER XI.

ERASURES.

The alteration of the figures and amount written on a cheque is generally effected by erasure. At one time chemicals were used for this purpose, but fortunately the modern cheque is forgery-proof in this respect. No means are known to chemists by which ordinary writing can be removed from a cheque without leaving a sign too p.r.o.nounced to escape detection.

But even erasure on a cheque is extremely difficult, and the experienced eye of the average bank teller can detect it in the vast majority of cases. Frauds perpetrated by this means are very rare, and are usually the result of gross carelessness on the part of the person accepting the doc.u.ment so altered.

The more frequent form of cheque fraud is effected by adding to such words as six, seven, eight and nine. The addition of _ty_ and _y_ is all that is necessary. But the ordinarily careful business man never leaves sufficient blank s.p.a.ce between his words to admit of this addition, while there are few bank tellers who do not carefully scrutinise a cheque made out for these larger amounts.

It may be accepted as a satisfactory fact that cheque forgery is not only extremely difficult, but rarely successful. Great frauds are usually perpetrated by means of other instruments, such as bills of exchange, credit notes, &c.

An erasure is the easiest thing to detect if looked for. To begin with it is only necessary to hold a scratched doc.u.ment to the light to have the alteration revealed.

Erasing must of necessity remove part of the surface of the paper which is made noticeably thinner at the spot erased.

In nearly every case the writing that has been added to the erasure is blurred, owing to the rough and absorbent character of the paper. Expert forgers have devised means of counteracting this by rubbing in some substance which partially restores the original smoothness and mitigates the blurred appearance. But such devices ought not to be successful for they are so easily detected.

As a matter of fact the only chance the forger of an erased cheque has lies in the carelessness of the teller. Any crowding of words and unequal s.p.a.cing in the filling up of a cheque ought to excite suspicion and provoke careful and closer scrutiny, and, it may be added, it generally does.

The addition of letters intended to increase the value of a number, such as the adding of _ty_ to six or seven, is easy of detection if properly looked for.

It is safe to a.s.sume that the addition has been made long after the original word was written, and the point of junction can be detected by the aid of a good gla.s.s.

Had the word been originally written sixty, the chances are that there would be no perceptible break between the _x_ and the _t_. Few persons write such short words in a disconnected manner. On placing the word under an ordinary gla.s.s the point of junction will be plainly apparent, and a microscope, or an enlarged photograph, cannot fail to reveal the fraud. Of course these latter tests will not be possible under the ordinary circ.u.mstances attending the paying out of a cheque over the counter, but when once the peculiarities of such alterations have been studied, it is marvellous how quick the eye becomes in recognizing them at a glance.

Erasure in writings on stout thick paper is not quite so readily noticed as those on thin paper such as cheques; but the same methods of examination will apply--holding the doc.u.ment to the light, or level with and horizontal to the eye. A very effective application of the latter test is to bend or curve the paper, making an arch. The bending has a tendency to stretch and widen the erased part, and if any smoothing substance such as starch or wax has been added to restore the gloss of the sc.r.a.ped portion, it will usually reveal itself by separating and coming away in dust or tiny flakes. This process may be accentuated by drawing the suspected doc.u.ment over a ruler, or, better still, a pencil, repeating the motion several times.

CHAPTER XII.

PENCILS AND STYLOGRAPHS.

It is obvious that writing executed with a pencil or the now much-used stylograph will differ in many respects from that performed by an ordinary pen. It is not too much to say that their use will eliminate many features and introduce new ones. This change is mainly brought about by the different way in which a pencil or stylograph is held in comparison with a pen. There is a much greater sense of freedom. The pencil can be, and is, turned and twisted in the process of making a stroke as a pen cannot be, and the signs of this freedom become apparent in a more rounded stroke. Even a writer whose characters are acutely angular shows a tendency to a more graceful outline. As a matter of fact, it is comparatively rare to meet a pencilled writing that is p.r.o.nouncedly angular.

The same remarks apply with only little modification to writing produced by the stylograph, and for the same reason--the ease and freedom with which the instrument is held.

There is no possibility of mistaking writing produced by a stylograph for that of an ordinary steel nib. The strokes are absolutely uniform in thickness. No nib-formed writing can be so, for it is impossible for a writer, however careful, to avoid putting pressure on his pen at some point; and the opening of the nib, however slight, must produce an apparent thickening.

Therefore, recognising these facts, the expert is always extremely careful in giving an opinion upon a writing produced by pencil or stylo unless he have ample specimens of the writer's productions done with these instruments.

At the same time, although an absence of characteristics present in pen writing would be noticeable, the main features would exist: for example, the s.p.a.ce between words and letters would be the same; the dot over the _i_ would be in its customary position; the bar of the _t_ would be of the same type as heretofore. The princ.i.p.al changes would be in the direction of a more uniform stroke with a tendency to greater rotundity.

Persons who habitually employ the stylo very frequently develop an unconscious habit of twisting the pen at certain points so as to form a deep, rounded dot. This occurs princ.i.p.ally at the ends of words and strokes. A magnifying-gla.s.s reveals this peculiarity at once, and, when discovered, notice should be taken of the circ.u.mstances under which this twisting is usually done. It will be found, most probably, that the trick is uniform; that is, certain letters or strokes are mostly finished with the dot.

There is a well-known public character who for years has employed no other writing instrument but the stylo. His writing possesses one peculiarity which is so habitual that in four hundred examples examined it was absent in only five. He forms this twist dot at the end of the last letter at the end of every line. The inference and explanation is that, in raising the pen to travel back to the next line, he twists it with a backward motion in harmony with the back movement. Another trick is to make the same dot in words on which he appears to have halted or hesitated before writing the next. In every such case there is an extra wide s.p.a.ce between the word ended by a dot and that which follows. It would appear as if the writer mechanically made the dot while pausing to choose the next word. This is a striking example of the unconscious hand-gesture.

Something akin to it occurs in the handwriting of a famous lawyer. Here and there in his letters will be noticed a faint, sloping, vertical stroke, like a figure _1_. Those who have seen him write explain it thus. While hesitating in the choice of a word he moves his pen up and down over the paper, and unintentionally touches it. It is such slips as these which often supply the expert with valuable clues to ident.i.ty.

When they occur they should be carefully examined, for in the majority of cases a reason will be found for their presence.