610 INFECTION AND IMMUNITY. 



serum of As stated above, Marmorek discredits tuberculin 

 as the specific toxin of the bacillus. His "true" 

 toxin is prepared by growing young and virulent 

 bacilli ("primitive" bacilli) in a medium which 

 contains leucotoxic serum, liver extract, glycerin 

 and bouillon. The leucotoxic serum is prepared 

 by immunizing calves with the leucocytes of 

 guinea-pigs. Theoretical considerations which we 

 need not detail suggested the use of this medium. 

 The cultures are filtered after a few days of growth 

 and the formation of tuberculin is avoided as much 

 as possible. The immunization of horses with this 

 filtered toxin yields the antitoxic serum of Mar- 

 morek. Conflicting reports concerning its value 

 are published from French sources. Schwartz an- 

 nounces the complete cure of a case of tuberculosis 

 of the larynx, and another of virulent tuberculosis 

 of the conjunctiva and cornea by the exclusive use 

 of Marmorek's serum. 



immnniza- Both Maragliano and Behring affirm that the 

 immunizing substances are excreted in the milk of 

 cows which have been strongly immunized against 

 tuberculosis, and both have suggested that the use 

 of such milk by infants may render them more re- 

 sistant to tuberculosis. 



The agglutination reaction has been suggested 

 by Courmont and Arloing and others as a means of 

 diagnosis in tuberculosis. Others who criticise this 

 idea affirm that agglutinins are not developed suf- 

 ficiently in tuberculosis to render the test of 

 value, and that the serum of normal man may be 

 as highly agglutinating as that of the tuberculous. 

 In view of the fact that the tubercle bacillus grows 

 in coherent masses in ordinary cultures special 

 manipulations are necessary to render it suitable 



