HISTORIC DEVELOPMENT OF IMMUNOLOGY 73 



horse. In the following year our laboratories 

 introduced to the medical profession the re- 

 fined and concentrated Diphtheria Antitoxin, 

 prepared as directed by Robert B. Gibson. By 



Emil Abderhalden (1877-). 



this process, only those serum proteins which 

 are insoluble in a half-saturated solution of 

 ammonium sulphate and soluble in a saturated 

 solution of sodium chloride are retained; all 



