BLOOD. 27 



CHAPTER n. 



BLOOD. 



The microscope is daily becoming a more and more 

 important aid to legal investigation. An illustration 

 of this occurred not long ago, in which a murder was 

 brought home to the criminal by means of this instru- 

 ment. Much circumstantial evidence had been adduced 

 ao-ainst him, amono; which was the fact, that a knife in 

 his possession was smeared with blood, which had dried 

 both on the blade and on the handle. The prisoner 

 strove to turn aside the force of this circumstance by 

 asserting that he had cut some raw beef with the knife, 

 and had omitted to wipe it. 



Tlie knife was submitted to an eminent professor of 

 microscopy, who immediately discovered the following 

 facts : — 1. The stain was certainly blood. 2. It was 

 not the blood of a piece of dead flesh, but that of a 

 living body ; for it had coagulated where it was found. 

 3. It was not the blood of an ox, sheep, or hog. 4. It 

 was human blood. Besides these facts, however, other 

 important ones were revealed by the same mode of in- 

 vestigation. 5. Among the blood were found some 

 vegetable fibres. 6. These were proved to be cotton 

 fibres, — agrreeino; -svith those of the murdered man's 

 shirt and neck-kerchief. Y. There were present also 

 numerous tessellated epithelial cells. In order to under- 

 stand the meaning and the bearing of this last fact, I 



