TAMPERED, ERASED, AND MANIPULATED PAPER

Prof. G. Brynlants of the Belgian Academy of Sciences, who has made the detecting of forgery and disputed handwriting a study for twenty years, recently made public an account of the researches he had made and deductions arrived at with a view of making known how frauds and alterations are made on checks, drafts, and business paper generally and how same can easily be detected. The system he recommends is now in use in nearly every bank in Europe and the result of his work and his recommendations should be carefully read and the system applied by the banks and business houses of the United States, when occasion requires.

The following article has been specially prepared for this work; and if its recommendations are carefully carried out it will prove a sure rule for the detection of forged and fraudulent handwriting:

“Although my experiments were not always carried on under the most favorable circumstances, their results were eminently satisfactory and will prove a boon to the banking and business world. A piece of paper was handed to me for the purpose of determining if part of it had been wet and if another part of it had been manipulated for the purpose of erasing marks upon it; in other words, whether this part had been rubbed. The sample I had to work upon had already gone through several experiments. I had remarked that the tint of the paper exposed to the vapor of iodine differs from that which this same paper assumes when it has been wet first and dried afterwards. In addition to this I realized that when sized and calendered paper, first partially wet and then dried, is subjected to the action of iodine vapor, the parts which have been wet take on a violet tint, while those which had not been moistened became either discolored or brown. The intensity of the coloration naturally varied according to the length of time for which the paper was exposed to the iodine.

“There is a very striking difference also when the water is sprinkled on the paper and the drops are left to dry off by themselves in order not to alter the surface of the paper.

“Thorough wetting of the paper will cause the sprinkled spots to turn a heavy violet-blue color when exposed to vapor while the parts which are untouched by the water will become blue.

“If, after sprinkling upon a piece of paper and evaporating the drops thereon, this piece of paper is thoroughly wet, then dried and subjected to the action of iodine, the traces of the first drops will remain distinguishable whether the paper is dry or not. In the latter case the trace of the first sprinkling will hardly be distinguishable so long as the moisture is not entirely got rid of; but as soon as complete dryness is effected their outlines, although very faint, will show plainly on the darker ground surrounding the spot covered by the first drop.

“In this reaction, water plays virtually the part of a sympathetic fluid, and tracing the characters with water on sized and calendered paper, the writing will show perfectly plain when the paper is dried and exposed to action of iodine vapor. The brownish violet shade on a yellowish ground will evolve to a dark blue on a light blue ground after wetting. These characters disappear immediately under the action of sulphurous acid, but will reappear after the first discoloration provided the paper has not been wet and the discoloration has been effected by the use of sulphurous acid gas.

“The process, therefore, affords means for tracing characters which become legible and can be caused to disappear, but at will to reappear again, or which can be used for one time only and be canceled forever afterwards.

“The usual method of verifying whether paper has been rubbed is to examine it as to its transparency. If the erasure has been so great as to remove a considerable portion of the paper, the erased surface is of greater translucency; but if the erasure has been effected with great care, examining same close to a light will disclose it; the erased part being duller than the surrounding surface because of the partial upheaval of the fibers.

“If an erasure is effected by means of bread crumbs instead of India rubber, and care is taken to erase in one direction the change escapes notice; and it is generally impossible to detect it, should the paper thus handled be written upon again.

“Iodine vapors, however, show all traces of these manipulations very plainly giving their location with perfect certainty. The erased surfaces assume a yellow brown or brownish tint. If, after being subjected to the action of the iodine, the paper on which an erasure has been made is wet, it becomes of a blue color the intensity of which is commensurate with the length of time to which it has been under the action of the iodine, and when the paper is again dried the erased portions are more or less darker than the remainder of the sheet. On the other hand when the erasure has been so rough as to take off an important part of the material exposure to iodine, wetting, and drying result in less intensity to coloration on the parts erased, because the erasing in its mechanical action of carrying off parts of the paper removes also parts of the substance which in combination with iodine give birth to the blue tint. Consequently the action of the iodine differs according to the extent of the erasure.

“When paper is partially erased and wet, as when letters are copied, the same result although not so striking follows upon exposing it to the iodine vapor after letting it dry thoroughly.

“Iodine affords in certain cases the means of detecting the nature of the substance used for erasing. Bread crumbs or India rubber turn yellow or brownish yellow tints and these are distinguished by more intense coloration; erasure by means of bread crumbs causing the paper to take a violet shade of great uniformity. These peculiarities are due to the upheaval of the fibers caused by rubbing. In fact this upheaval creates a larger absorbing surface and consequently a larger proportion of iodine can cover the rubbed parts than it would if there had been no friction.

“When paper upon which writing has been traced with a glass rod, the tip of which is perfectly round and smooth, is exposed to iodine vapor, the characters appear brown on yellow ground which wetting turns to blue. This change also occurs when the paper written upon has been run through a super-calender. If the paper is not wet the characters can be made to appear or be blotted by the successive action of sulphurous and iodine vapor.

“Writing done by means of glass tips instead of pens will show very little, especially when traced between the lines written in ink. The reaction, however, is of such sensitiveness that where characters have been traced on a piece of paper under others they appear very plainly, although physical examination would fail to reveal their existence, but a somewhat lengthy exposure to iodine vapors will suffice to show them.

“If the wrong side of the paper is exposed to the iodine vapor the characters are visible; but of course in their inverted position.

“If the erasure has been so great as to take off a part of the substance of the paper the reconstruction of the writing, so as to make it legible, may be regarded as impossible. But in this case subjecting the reverse side of the paper to the influence of the iodine will bring out the reverse outlines of the blotted-out characters so plainly that they can be read, especially if the paper is placed before a mirror. In some instances, when pencil writing has been strong enough, its traces can be reproduced in a letter press by wetting a sheet of sized and calendered paper in the usual way that press copies are taken, placing it on paper saturated with iodine and putting the two sheets in a letter book under the press, copies being run off as is usual in copying letters. The operation, however, must be very rapidly carried out to be successful. As a matter of fact the certainty of these reactions depends entirely upon the class of paper used. Paper slightly sized or poorly calendered will not show them.

“Another point consists in knowing how long paper will contain these reactive properties. In my own experience the fact has been demonstrated that irregular wetting and rubbing three months old can be plainly shown after this lapse of time. Characters traced with glass rod tips could be made conspicuous. I have noticed that immersing the written paper in a water bath for three to six hours will secure better reactions, but although these reactions are very characteristic they are considerably weaker.”