50 THE PROTEOMORPHIC THEORY AND THE NEW MEDICINE 



window sill, or scraped from the surface of a boot or a coin. In 

 this case the question as to whether the stain was caused by 

 human blood or by that of some animal might be the deciding 

 testimony in a murder trial. 



Here the method of procedure would be the same as before. 

 A solution being made from the blood stain and placed in a 

 test-tube, the trial fluid would determine whether the stain was 

 due to human blood. If the test proved negative, other tests 

 might determine what particular animal supplied the blood. In 

 a case reported by Professor Uhlenroth, for example, a blood 

 spot in the road, suspected to be of human origin, was found to 

 be from the blood of a pig. In another case blood stains on a 

 garment were reported as being partly human and partly due 

 to the blood of the sheep. In this case it was subsequently proved 

 in court that the wearer of the garment had committed a mur- 

 der, but that he had slaughtered sheep two weeks before the 

 murder. 



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 injec- 

 tions into the system of the serum of human blood or that of 

 some other member of the animal kingdom, according 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 inoculated with the blood 

 serum of a cat, will develop an anti- feline serum; and so for 

 all other tribes of animals including not merely mammals, but 

 birds, reptiles, and even crustaceans, such as the lobster and its 

 allies. 



The explanation of the development in the body of the rabbit 

 of the peculiar quality of blood that gives the anti-serum its 

 value in such tests as those outlined, is found in the fact that 

 the blood of almost any animal has a certain quality of toxicity 

 when injected into the veins of an animal of different species. 

 In some cases this action may be very virulent. 



For example, fifteen drops of the blood of an eel injected into 

 the veins of a dog weighing about thirty pounds may produce 

 death in seven or eight minutes. 



In another experiment ten drops of the blood serum of an eel 

 killed a rabbit of ordinary size in two-and-a-half minutes. The 

 foreign blood serum appears to attack the blood corpuscles, ren- 

 dering them functionless and presently dissolving them. 



