202 METHODS OF SERODIAGNOSIS. 



blood produced a serum haemolytic for the red corpuscles of 

 horses and mules. 



Similarly some mules, when hyperimmunized with mule or 

 horse blood, produced a serum haemolytic for horses and mules, 

 and donkeys, when hyperimmunized with horse blood, in some 

 instances yielded a serum haemolytic for horses and mules. 



The use of such serum for immunizing equities against horse- 

 sickness is thus prohibited, since its injection into equities would 

 be followed by results of a disastrous nature, ranging from the 

 production of hemoglobinuria (resulting from the haemolysis 

 occurring in vivo) tip to the death of the animal, depending on 

 the amount of isolysin present in the serum. A serum containing 

 these isolysins is not necessarily haemolytic for the corpuscles of 

 all the individuals of the species on whose blood it acts. 



These isolysins were never found to be produced in the case 

 of cattle used for producing anti-rinderpest serum. Lately, Todd 

 and White have found, however, that if guinea-pig complement 

 be added to such serum, it can then take on a haemolytic 

 action for ox blood cells. 



It was Ehrlich and Morgenroth who came to study the 

 nature of the lysins more in detail and to investigate the nature 

 of alexin and the other specific body formed in the blood of 

 animals used for the preparation of the lysins. These two bodies 

 concerned in lysis have received various names. Thus the alexin 

 di Bordet (a term originally suggested by Buchner, who applied 

 it to the bactericidal agent in serum of normal animals, regarding 

 it as being of the nature of a ferment ) was called complement by 

 Ehrlich, and was also termed cytase and addiment by others, 

 whilst the " substance sensibilisatrice " of Bordet came to be 

 termed amboceptor by Ehrlich ; and names such as copula, inter- 

 mediary body, interbody, immune body, preparator, fixator, etc., 

 were applied by others. 



The terms alexin and substance sensibilisatrice of Bordet, and 

 complement and amboceptor of Ehrlich, indicate the difference 

 in the views of these workers and their followers, regarding the 

 actions of lysins. 



Ehrlich and Morgenroth, investigating the action of haemoly- 

 tic serum, found that if such a serum was brought in contact with 

 the appropriate corpuscles at a temperature of o° C. no haemolysis 

 occurred at this temperature, and that if this mixture, kept a*: 

 this low temperature, was centrifugalised. the resultant super- 

 natant fluid, when removed, was capable of reactivating a haemo- 

 lytic serum previously inactivated by heating to 55 ° C, thus acting 

 as a normal serum would ; whilst if the corpuscles remaining, 

 after centrifugalizing the mixture, were suspended in a physiolo- 

 gical salt solution ( .85 % or .9 % sodium chloride in water) and 

 exposed to a temperature of 37 C, they did not undergo 

 haemolysis until a supply of fresh normal serum was added. 



As a result of their experiments, they concluded that the 

 substance sensibilisatrice of Bordet, which they now termed 

 amboceptor, was capable of combining with the red corpuscles 



