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STRONG. 



THE AGGLUTINATING PROPERTIES OF THE BLOOD IN IMMUNIZED 

 HUMAN BEINGS. 



A stud)' of the agglutinating properties in the hlood of a number of 

 persons who had been vaccinated against plague, as well as of several 

 cases who had suffered with the disease, is summarized in the following 

 table. The blood was collected and tested from the vaccinated cases, 

 from one week to ten days after the inoculation. It was taken from those 

 convalescent from plague ten days after the subsidence of the fever. 

 In the two cases in which it was obtained at autopsy, the patients had 

 lived ten and fourteen days, respectively, after the onset of the disease. 

 In order that the tests might be carefully and repeatedly made, from 10 

 to 20 cubic centimeters of blood was collected in the living cases from 

 a vein of the arm. In the majority of instances reactions were at the 

 same time performed with fresh, normal human serum. The sera were 

 all tested within a day or two after the blood was drawn. A second 

 transplant 24-hour culture of the virulent strain was employed in all 

 the tests. 



Table No. X. — Tests of the agglutinating value of human immune sera. 



Case No. 



Manner of inoc- 

 ulation. 



Dilutions. 



Results and remarks. 



I 



T \i oese "Pest 



1:2; 1:5; 1:10; 



After 1 hour all negative. After 16 hours 





A virulent;" 1 



1:20: 2 controls 



the precipitation of the bacteria is quite 





week later i 



(no serum). 



marked in all of the tubes but not so 





oese "Pest 





marked or of so dense a nature in the 





A virulent." 





control tubes. 







•1:2; 1:5; 1:10; 



After 1 hour all negative. After 16 hours 







1:20; 1:50; 



sediment in an the tubes but more 







1 : 100; 2 con- 



marked in the tubes containing serum 







trols (no serum). 



than in the control tubes. The same 



I 



_do _ _ 





sera tested again the following day with 

 the same results. 













1 control horse 



Positive after 1 hour. 







pest immune 









( serum. 









1 : 10; 1 : 20: 4 



After 1 hour all negative. After 16 hours 







controls ( n o 



sediment in all the tubes; more marked 







serum). 



in all tubes containing s rum than in 

 control tubes. The same sera were 





^ 



, 



tested on the following day with similar 



II 



i oese "Pest 





results. 





Avirulent." 



1 2 controls with 

 normal human 

 serum, dilu- 





t 





tions 1:10: 1:20. 









1:10; 1:20; 1:40; 



After 2 hours distinct precipitation of bac- 







1:80; 1:160; 2 



teria in dilution of 1:10; after 2± hours 







controls with- 



precipitation appears also in dilutions 



III 



2 oesen "Pest 

 Avirulent." 



out serum. 



1 control normal 

 human serum, 

 1 : 20. 



of 1 : 80 and 1 : 160. Remaining tubes 

 show no precipitation. 



