1890.] MICROSCOPICAL JOURNAL. 125 



ing the difterences of the original and additional inks. These difterences 

 may be present, as follows : Some inks in drying assume a dull or shiny 

 surface. If in sufficient quantity the surface may become cracked, pre- 

 senting, when magnified, an appearance quite similar, but of a different 

 color, to that of the dried bottom of a clayey pond after the sun has 

 baked it for a few days. The manner in which the ink is distributed 

 upon the paper, whether it forms an even, somewhat regular, border or 

 spreads out to some extent, are factors which may also be noted. The 

 color of the ink, by transmitted or reflected illumination, is a very im- 

 portant factor. This, in one case, proved of great importance, and 

 demonstrated the addition of certain words, which completely annulled 

 the value of the document, involving several thousand dollars. And in 

 a case where the lines of a document were written over with the idea of 

 entirely covering the first written words, the different colors of the ink 

 were concealed from the magnified image as seen under reasonable low 

 powers of the microscope. 



Special attention is desired to the examination with the microscope 

 of written documents, United States currency, printed matter, etc., as 

 to their genuineness from a legal standpoint. The principal feature 

 in the examination of written and printed documents is in the erasures 

 and the additions, in the different coloring of different inks applied, and 

 the mode of their execution. 



Erasures can be accomplished either with a knife or by a chemical 

 preparation. The former process is the one commonly resorted to, and 

 is effected in the following manner : With a well sharpened knife-blade 

 the surface of the paper is carefully scraped until all objectionable let- 

 tering and wording is supposed by the naked eye to have disappeared. 

 With a microscopical examination you can at once detect the impres- 

 sion made by the stroke of a pen. Even the different colors of the ink 

 are still to be seen with the microscope. 



The second method being by a chemical preparation. The ink is 

 made soluble and then easily removed from the paper by means of a 

 blotter or absorbent cotton. This method is also an incomplete one, 

 and the letters can easily be made out by close observation, where a 

 chemical preparation has been used for erasing. In most cases it leaves 

 a stain, and the fibres of the paper are more or less injured by the chem- 

 icals used, always leaving evidence that the document has been tam- 

 pered with. 



Geo. E. Fell, in his paper, says the eye of the individual making the 

 erasure is certainly not sufficient, and even with the aid of a hand mag- 

 nifier the object might not be effectually accomplished. The detection 

 of an erasure made by the knife is a very simple matter, and may be 

 accomplished by the novice. An investigation may be made by simply 

 holding the document before a strong light, and this is usually all that 

 is necessary to demonstrate the existence of an erasure of any conse- 

 quence. This is, however, a very different matter from making out the 

 outlines of a word or detecting the general arrangement of the fibres of 

 the paper, so as to be enabled to state whether writing has been exe- 

 cuted on certain parts of the document. Again, when we enter into 

 the minutiae of the subject, we find that the compound microscope will 

 give us results not to be obtained by the simple hand magnifier. 



On several occasions I have had the opportunity of demonstrating 



