Archive image from page 328 of Discovery Discovery discovery0304londuoft Year: DISCOVERY 319 It is owing to the use of different pigments for this provisional colouring matter that it is often possible to distinguish between the inks of different manu- factures in \vriting. B3' treating the writing with dilute acid the iron tannate may be bleached, leaving the aniline dye available for examination. Whether or not provisional colouring matter of an ink is an aniline dye may be of importance. During the last years, entries in famUy Bibles have been produced in support of claims to a pension,
Archive image from page 328 of Discovery Discovery discovery0304londuoft Year: DISCOVERY 319 It is owing to the use of different pigments for this provisional colouring matter that it is often possible to distinguish between the inks of different manu- factures in \vriting. B3' treating the writing with dilute acid the iron tannate may be bleached, leaving the aniline dye available for examination. Whether or not provisional colouring matter of an ink is an aniline dye may be of importance. During the last years, entries in famUy Bibles have been produced in support of claims to a pension, but the presence of an aniline dye in the ink, on more than one occasion, has proved conclusively that the entries were forgeries. The different proportions of iron and tannin from various sources also contribute to the character of the reaction given in ink by writing. An expert, after a series of systematic tests with his reagents, and using an apparatus called a tintometer to compare the changes in colour of the ink produced by the reagents, can frequently tell one kind of a blue-black ink from another with certainty. The first occasion on which the method was used in an English Court of Law was at the trial of Brinkley in 1907, when it was proved that an alleged will was written in three different kinds of ink. Judging the approximate age of an ink is generally much more difficult than deciding the identity of two inks. There are certain distinct differences in the microscopical appearance of very old and of modern inks. The latter show a much more crystalline appearance, mainly due to the pigment attached to the fibres of the paper, and it is often possible to see dark margins to the lines due to the greater absorption of pigment at the places where the pressure of the divided pen nib was applied. This is illustrated in Figs. I and 2. It was mentioned above, when the properties of an iron-gall ink were being described, that comparatively new inks are smudged when treated w
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Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
