The Antitoxins 131 



peutic value of the plasma was not appreciably impaired through the 

 process of eliminating the albumins and other non-antitoxic proteins 

 by the salting out methods employed, and the final dialyzation of 

 the concentrated product, thus disproving the objection of Cruveil- 

 hier* on this point. 



Tetanus antitoxin was first prepared by Behring and Kitasato.f 

 It can be employed for the prevention or cure of tetanus. For the 

 former purpose, hypodermic injections of the serum may be given in 

 cases with suspicious wounds, or the wounds may be dusted with a 

 powder made by pulverizing the dried serum. For treatment the 

 serum must be administered in frequently repeated large doses by 

 hypodermic or intravenous injection. The results are less brilliant 

 than those attained with diphtheria antitoxin because of the avidity 

 with which the cells of the central nervous system take up the tetanus 

 toxin, and the firmness of the union formed. An analysis of a great 

 number of cases has, however, shown that the recoveries following 

 the free administration of the serum exceed those effected by other 

 methods of treatment by about 40 per cent. 



By the gradual introduction of tetanus toxin Behring and Kita- 

 satot have been able to produce a powerful antitoxic substance in 

 the blood of animals. 



The method of obtaining tetanus antitoxic serum is like that 

 employed for securing diphtheria antitoxic serum (q.v.). 



Madsen§ found that for each of the specific poisons, tetanolysin 

 and tetanospasmin, a specific antitoxin is produced, the one annul- 

 ling the convulsive, the other the hemolytic, properties of the toxin. 

 The usual therapeutic serums contain both of these. 



Different standards for measuring the strength of the tetanus 

 toxin and different definitions of the unit of measurement are 

 given in different countries, so that great confusion and dissatis- 

 faction were experienced until a special committee of the Society 

 of American Bacteriologists met in New York, Dec. 27 and 28, 

 1906, and in collaboration with the United States Public Health and 

 Marine Hospital Service, Hygienic Laboratory, formulated a 

 standard unit which has become the legal unit of measurement for 

 the United States. It is thus defined: 



"The immunity unit for measuring the strength of tetanus 

 antitoxin shall be ten times the least quantity of antitetanic serum 

 necessary to save the life of a 350-gram guinea-pig for ninety-six 

 hours against the official test dose of a standard toxin furnished by 

 the Hygienic Laboratory of the Public Health and Marine Hospital 

 Service." The unit is thus officially defined, Oct. 25, 1907, in 

 Treasury Circular No. 61. 



Testing tetanus antitoxic serums immediately became a matter 



* "Ann. de I'Inst. Pasteur," 1904, xviii, p. 249. 

 t "Deutsche med. Wochenschrift," 1890, No. 49. 

 t Ibid. 

 § "Zeitschrift fur Hygiene," 1899, xxxni, p. 239. 



