FORENSIC MICROSCOPY. 13S 



to hasmatin (methsemoglobin) may show a spectrum 

 with the combined bands of both. The spectroscopic 

 test is, of course, given by the blood of any red-blooded 

 animal. It is extremely delicate and has yielded posi- 

 tive results with stains over a hundred years old. 



4. The Study of Finger-prints. — The identification of 

 individuals, so important not only in criminology but in 

 a multitude of civil and criminal cases, has been greatly 

 facilitated by the anthropometric system of M. Ber- 

 tillon. This rests upon the principle that variations in 

 the proportions of the body, when a number of separate 

 features are measured, are so characteristic that a defi- 

 nite formula may be obtained from them, which shall 

 differentiate each individual from any other. Commonly 

 the length and breadth of the head and the length of the 

 left middle finger, the left forearm, and the left foot form 

 a primary basis for classification to which other general 

 characteristics and special individual peculiarities may 

 be added ad infinitum. 



The use of the finer details of the structure of the skin 

 to supplement the Bertillon system was first suggested 

 by the distinguished English biologist, Francis Galton, 

 though Sir William Herschel had previously used finger- 

 prints as a means of personal identification. Recently 

 Professor H. H. Wilder's investigations have shown the 

 great importance of these structures in the study of 

 heredity. If the bulb below the tip of the finger be 

 pressed first upon a metal surface covered with a thin 

 film of printer's ink, and then upon a paper or card, 

 a permanent record will be obtained of the arrangement 



