FILTRATION OF IMMUNE SERUMS. 



337 



Table III. — Antidiphtheric serum unfiltered and filtered mixed with diphtheria 

 toxin and tested on guinea pigs. 



Portion of serum. 



Quantity of— 



Results. 



Serum. 



Toxin. 



A 



cc. 



J Tk 



sis 



33 !J 



sis 



Test dose— 

 Test dose.— 

 Test dose... 

 Test dose... 

 Test dose.— 

 Test dose... 

 Test dose.— 

 Test dose... 

 Test dose... 

 Test dose- 

 Test dose- 

 Test dose... 



Test dose 



Test dose... 

 Test dose- 

 Test dose- 



Lived. 



Lived. 



Died. 



Died. 



Lived. 



Lived. 



Died. 



Died. 



Lived. 



Lived. 



Died. 



Died. 



Lived. 



Lived. 



Died. 



Died. 



V 



N-. 



W ._ 





The results shown in Table III would suggest a loss of antitoxin in 

 portion W, but owing to the small number of animals iised a definite 

 statement can not be made. 



A few cubic centimeters of filtrates X and W planted in agar yielded 

 no bacterial growth. 



EXPERIMENT NO. IV. 



A quantity of typhoid agglutinating serum was divided into four portions 

 A, V, N and W. Portion A remained unfiltered, and portions V, N and W were 

 passed through the corresponding Berkefeld filters. After filtration of portions 

 V, N and W the agglutinating values of the different portions were determined on 

 a suspension of Bacillus typhosus. 



