384 Mr. A. H. Caulfeild. Inhibitive and Fixation [Aug. '24, 



Table VI.— Protocol 18.11.10. 





Haemolysis at end 

 of 2 hours. 



Ext. IV— 

 1-0 c.c. 

 66 „ 

 0-5 „ 



Saline l'O 



5.C. 





Complement (2 units + ) l'O c.c 



Some — . 

 Almost complete. 



0-66 C '^' 



Saline 2'0 







Complement (2 units + ) l'O c.c. 



Almost complete. 



0-5 „ 











1-0 c.c. 

 66 „ 

 0-5 „ 



Saline 4*0 



.c. 





Complement (2 units + ) l'O c.c 



Complete. 



1-0 c.c* 

 1-0 „ 

 1-0 „ 

 0-5 ., * 

 0-5 „ 

 05 „ 



S. 1354, 0. 



3 c.c. 



2-0 c.c. 

 4-0 „ 



2-0 „ 

 4-0 „ 



Complement (2 units + ) l'O c.c. 



Almost complete. 

 Complete. 



1-0 c.c* 

 1-0 „ 

 1-0 „ 

 5 ., * 

 05 „ 

 0-5 „ 



S. 10, 0-3 c 





2 c.c. 

 40 „ 



2-0 „ 

 40 „ 



Complement (2 units + ) l'O c.c. 



Almost complete. 

 Complete. 



1-0 c.c* 

 10 „ 

 1-0 „ 

 0-5 „ * 

 0-5 „ 

 05 „ 



S. 860, 0-3 



+ saline 

 + » 



2-0 c.c. 

 4-0 „ 



20 ., 

 4-0 „ 



Complement (2 units + ) l'O c.c. 



None. 



Almost none. 



* These tubes were completed to a unit : as elsewhere the unit was actually 0'5 c.c, so that in 

 reality but half the quantities here quoted were used. Sera 1354 and 10 were inhibitive, and 

 Serum 860 indifferent. 



represents specific fixation. From many observations made witb sera from 

 man and animals with saline and one unit of complement, it is evident that 

 every variation from complete to no haemolysis may result. If one takes into 

 consideration the amount of prevention induced by serum and that by antigen 

 a very considerable check is afforded for otherwise "doubtful fixation 

 reactions." This explanation with certain sera (S. 860, Table VI), however, is 

 not sufficient to explain the end results as shown in the first and second 

 dilutions. For here, were the end reactions not specific, the addition of saline 

 would modify them. This serum has on several occasions given no haemolysis 

 with the first three antigen dilutions. The third and fourth dilutions could 

 not be made in Table VI because of lack of serum. The increased anti- 

 complementary conditions as shown in the third dilution (usually 1/40 or 



