140 ELEMENTS OF APPLIED MICROSCOPY. 
yield values from which the deviations of the writer are 
rarely great. Composite photographs of signatures, etc., 
are important aids in work of this sort. In the second 
place, more minute differences exist which can be detected 
only under the compound microscope. These are of three 
magnitudes. First, any long lines show certain varia- 
tions of direction whose number and nature vary with 
the writer. Second, much finer fluctuations occur, visible 
only under the compound microscope, in the shape of 
vertical deviations from side to side and changes in 
width due to periodic changes in the pressure of the pen- 
point. Third, on one or both margins of the line are 
still more minute lateral serrations. “These vertical and 
lateral variations are both illustrated in Fig. 52. They 
are, of course, influenced more or less by paper and 
writing utensils and by the physical and mental condi- 
tion of the writer; yet the size, position, and number of 
the waves, swellings, and notches are so related to the 
nervous organization of the writer, and differ so markedly 
with different individuals, as to yield important aid in 
the identification of handwriting. 
REFERENCES. 
Bascock, J. F. The Medico-Legal Examination of Blood and 
other Stains, Hairs, and Fibres. New York, 1894. 
Frazer, P.  Bibliotecs, or the Study of Documents. Phila- 
delphia, 1901. 
Gatton, F. Finger Prints. London, 1892. 
Gatton, F. Finger-print Directories. London, 1895. 
Roscor, H. E. Spectrum Analysis. London, 1870. 
Taytor, A. S. A Manual of Medical Jurisprudence. New 
York and Philadelphia, 1897. 
Woop, E. S., WirHaus and BECKER. Medical Jurisprudence, 
Forensic Medicine and Toxicology. New York, 1894. 
