Science and the Criminal

ethods-Typewritten Matter-Examinations of

sed upon the use of the microscope, which will frequently r

tly roughened surface of the paper, where the fibres have been disturbed in the process of erasure. A notable example of this was seen in the Whalley will

to be put in evidence in a dispute as to some property had originally contained the word

ess at that place, but under the microscope the ruffled fibres on the surfac

ng the erased place with a solution of rosin in spirit, which leaves a

and when the paper has been dried again it will be found that this part, which will now be free

ten cause a blue coloration (due to starch) upon the moistened surface from whic

reference has been made, in which erasure of the letter "y" had been suspected fro

s not to require any magnification. As a rule, however, it is preferable to use only one drop of a reagent, and to follow closely under

is frequently indicated by the paper being thinner and more trans

a strong light and the camera, the negative will show a darker area corr

h the light falling obliquely upon the paper, the fibres that had been roughened by the erasure would be v

as upon blotting paper, and although this may be so slight as to escape the notice of the naked eye, it will be plainl

arily attract notice-will appear as a dark blotch upon a photographic reproduction. It has frequently been claimed that it is possible to distinguish between different kinds of ink by means of photography. Since inks contain provisional colouring matters which ca

tensity appear upon the negative, but these are not any more pronounced than the differences obvious to the

stinguish differences in form rather than in colou

iphering the words in faded ink upon old documents, for the yellow

g alterations in documents, and it has been found particularly useful for d

es is just as effective as the latter. In the examination of wills, for instance, it is necessary to obtain the express permission of the President of the

obtain what practically amounts to a record of the microscopical appearance. And the process has the additional advantage over microscopical examination that a large portion

tters with much less risk of detection than in the case of letters written in ordina

than the differences between different kinds of writing ink, and the proof of

carbon, and are, therefore, unlike most typing inks, exceedingly permanent, and it is also possible to distinguish bet

y a study of the typing it is frequently not a difficult matter with the

nd to give faults in their relative position, which are usually reproduced every time those letters are struck. Thus, for instance, an "a" may be a little above the line and an "r" fall too much to the right, and these peculiarities will almost invariably recur throughout every scrap of writing d

bout a year ago. It was suspected that a letter had been written in collusion with a clerk in a certain

hat the faults of alignment in both were identical. Wherever a letter, or combination of letters, in the one fell above or below the line, the

olet type, contained the same pigment, and the wa

the same machine. As a matter of fact, this proof of collusion did not carry the weight that

f strokes of writing only ten thousands of an inch across, and in some cases to prove in this way that a certai

will probably make a preliminary outline with a

y will case described on another page. In some instances the particles of the graphit

edges of the letters or any break between one part of a letter and another appear much more pronounced when examined in this way, for all faults are enormously intensified. Thus the figure "

A is shown the result of an attempt to change the number "11" into "17" by the addition of a stroke to the top of the second "1." The small inset represents th

stroke or part of a letter may touch some of the original writing,

largement of the cross stroke of the "t" in "date" and the top of the capital "C" in the signature (Fig. C), that the alleged older wri

where the perforations which are in common use as a means of preventing fraud had been carefully filled in, and new perforations made. Fig. D shows that a

RED

D PERF

by means of the Cam

mission of

ter writing was introduced, and in the crease thus formed the sizing on the surface of the paper had become worn, leaving the fibres m

in visible, it is frequently possible to render the characters visible once m

the iron in the ink) upon the white background of ash. In the case of inks that do not contain iron, or w

eat during the incineration, so as not to burn away the graphite. Marks done with a red pencil are, as a rule, burned

render the characters visible again, except when, as

ntial for the successful working of the process is that the paper itself shall yield a coherent white ash. In the case of common varieti

crease the amount and coherence of the ash by painting the reverse side of the charred paper with a solution of a mineral fixative agent, such as alumin

they may be rendered firm enough to handle by applying a solution of collodion to the reverse side, which on

the contraction of the ash of the paper during the incineration is

d writing may also be mad

e as 1826, appear to have afforded peculiar temptations to for

GED R

N OF T

mission of

TINGUISH OLD

PAG

en the years 1797 and 1811, 471 people were convicted o

d was 10,342; in 1815, 14,085; in 1816, 21,860; in 1817,

d be circulated, caused hundreds of people to take up the trade of forgery, until at le

which could not be imitated, and as a result of this outcry, a committee of scientif

submitted to them was proof against skilful imitation. Most of the forged notes had been clumsi

, that the Bank placed a private mark upon their no

by the amount of public money that was spent in the prosecution of the forgers, and the

, there were 242 prosecutions,

nk was forced to allow the culprits to plead guilty to a minor c

twenty or thirty convicted forgers awaiting execution, though the death

these prisoners, 17,874 were acquitted, while out of the remaining 75,844 sentence of death was passed upon 7,770, though not

ries the abolition of the issue of one pound notes, which took