856 SUMMARY OF CURRENT RESEARCHES RELATING TO 



measure a series of corpuscles accurately enough to discriminate 

 human blood from that of an ox, pig, horse, or sheep. 



Lastly, to make assurance triply sure, lift up the thin glass cover, 

 wipe olf the tiny drop of blood-solution and clot you have been 

 examining on the folded edge of a thin piece of moistened blotting- 

 paper, let fall upon it a little fresh tincture of guaiacum and then a 

 drop of ozonized ether, which will at once strike the dark-blue colour 

 of the guaiacum test for blood. 



In this way I have actually obtained these three kinds of evidence, 

 to wit, that of spectrum analysis, that of the Microscope, and that of 

 chemical reaction, from one single particle of blood, which, judged 

 by a definite standard,* certainly weighed less than y^^g^^, and 

 probably less than 25-^00 of a grain." 



Microscopical Examination of Handwriting — Detection of 

 Forgeries by the Microscope. — We append the remarks f of Dr. 

 E. H. Ward, of Troy, U.S.A. (President of the Bufi"alo Meeting of the 

 American Society of Microscopists), on this subject, which we referred 

 to at p. 946 of vol. ii. : — 



" The examination of handwriting, with a view to determine its 

 authorship, its genuineness, its age, and whether or not it has been 

 altered from its original form and intent, is one of the most recent 

 uses of the Microscope, and one, the importance, the reliability, and 

 frequent applicability of which has but recently become known, and is 

 even now not generally realized. Perhaps this is to be accounted for 

 by the fact that large general experience, judgment, and tact in the use 

 of the instrument, and skill in the manipulation, though necessary to 

 this particular work, are not, in themselves, an adequate preparation 

 for it. Much special study and special practice are required before 

 anything useful can be done, or important should be attempted. But 

 to a person really at home in the study of handwriting, both with and 

 without the Microscope, this instrument furnishes a ready means for 

 its accurate analysis. Those who are governed, not by respect for 

 the rights of others, but only by the expectation of consequences that 

 shall afiect themselves, cannot learn too soon, or too well, the fact that 

 writing can scarcely be changed after its original execution, so adroitly 

 that the Microscope cannot detect the falsification. 



The face of the paper, when once marred by disturbing the 

 position of the fibres, can never be restored, and hence scratching and 

 erasure can be recognized, though performed with consummate skill, 

 and not distinguishable by other means. Inks which are alike to the 

 unaided eye, are marked under the lenses by consjHcuous differences 

 of shades or colour, or density or purity, or chemical composition. 

 Lines which look simple and honest may show themselves as re- 

 touched or altered by the same or by a different hand or pen or ink ; and 

 lines drawn upon new paper may look different from those drawn 

 after it is old. The Microscope does not give any direct information 

 as to the precise age of writing, but if used with sufficient caution it 



* See 'Handbook of Medical Microscopy' (Philadelphia, 1871), p. 283. 

 t Proc. Anier. Soc. Microscopiats, 1880, pp. 46-8. 



