JUGGLING WITH LIFE 



of the sheep. In this case it was subsequently proved 

 in court that the wearer of the garment had com- 

 mitted a murder, but that he had slaughtered sheep 

 two weeks before the murder. 



The importance of such a test from a medico-legal 

 standpoint is obvious. It has been shown that the 

 test can be applied to blood stains on the most varied 

 materials, including wallpaper, wood, stone, coal, 

 coke, straw, rubber, linoleum, silver and copper coins, 

 and even shoes that had been blackened after the 

 blood was spattered over their surface. Various im- 

 plements that had figured in murder trials were 

 supplied by Scotland Yard to the Cambridge Labor- 

 atory to discover whether the tests could be applied 

 to blood stains of long standing. It was found that 

 the age of the stain made no particular difference. 

 Blood stains of twenty-eight and thirty years' stand- 

 ing on knives and razors responded to the test and 

 gave unequivocal evidence of their human origin. 



HOW THE TEST FLUIDS ARE DEVELOPED 



A word now as to the production of the magical 

 fluid with which such tests are operated. The fluid 

 consists of a portion of blood serum drawn from the 

 veins of a rabbit. The peculiar properties of the 

 serum have been developed by repeated injections 

 into the system of the serum of human blood or that 

 of some other member of the animal kingdom, ac- 

 cording to the particular type of test that is to be 

 made. 



A rabbit inoculated with human blood develops 

 a so-called anti-human serum. Another rabbit in- 



161 



