858 SUMMARY OF CURRENT RESEARCHES RELATING TO 



asserts itself; and this revelation often becomes more positive by 

 reason of the elaborate efforts that are made to suppress it. 



Things are overdone from fear, which would have been negligently 

 done from habit, not to speak of gross blunders proceeding from the 

 same source. I once examined a disputed signature from which had 

 been carefully scratched out a line, immaterial and inconspicuous, 

 which conformed to the habit of another person interested in the case, 

 but not to the habit of the ostensible author of the writing. 



Furthermore, the genuineness of a writing may often be disproved 

 by the very success with which it followed its copy, reproducing its 

 mistakes, idiosyncrasies, or its adaptations to its own special surround- 

 ings, in which respects it may correspond too accurately with some 

 one genuine signature (in the hands, for instance, of a suspected 

 person), but differ unquestionably from the ordinary habit of the 

 reputed author. Modifications of style by disease, as paralysis, may 

 present similarly decisive discrepancies or coincidences. There is a 

 peculiar tremor, too, about the writing of an individual, which is 

 dependent on the physical conformation of the writer, as related to his 

 habits of position, touch, and motion, which is quite characteristic, as 

 it can be neither imitated nor concealed. 



All these investigations in respect to writing can be best pursued 

 with the aid of the Microscope, and some of them are entirely depen- 

 dent upon it. For general view of the words a four or three inch 

 objective is best adapted ; for special study of the letters, a one-and-a- 

 half inch ; and for minute investigation of the nature of the lines or 

 character of the ink, a two-thirds or four-tenths. The lenses, except 

 the last, should be of the largest angles ordinarily made, and all should 

 be of flat field and of the best possible definition. The microscope- 

 stand should have a large flat stage, though it is generally preferable 

 to use a small portable stand which can be moved freely over the 

 paper and focussed upon it at any point without the use of a stage. 

 For this purpose I sometimes use a tank Microscope, but more 

 frequently a pocket Microscope, with its tube prolonged through the 

 stage by adapters, so that it focusses directly upon the table. Even so 

 large an instrument as Zentmayer's Histological may be so used to 

 advantage, though a lighter form and smaller size is far more con- 

 venient and sufficiently steady for this work. A medium-sized bull's- 

 eye is sufficient for the purpose of illumination, and good judgment is 

 more important than, if not incompatible with, the employment of an 

 ostentatious and unnecessarily elaborate apparatus." 



Professor Lester Curtis also read a paper* before the State Micro- 

 scopical Society of Illinois, in December 1879, on the "Microscopical 

 Examination of Signatures," in which, amongst other matters, he deals 

 with the process for determining which of two lines which cross each 

 other was written first — the determination being easy where ink has 

 been used, but impossible in the case of pencil, which leaves a film on 

 the surface of the paper of an imperceptible thickness, so that no 

 matter how many marks cross at any one place the surface is not 

 raised. 



* Amer. Mon. Micr. Journ., i. (1880) pp. 124-9. 



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