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



inhibitive reaction ; Serum 30, from a dog injected with Vaughn's non-toxic 

 tuberculin, gave complement fixation. Both sera were treated as follows : 

 On November 29, 1910, 1*5 c.c. serum was added to 5 c.c. of a 1/10 

 solution of stock antigen extract, and the mixture brought to 10 c.c. with 

 saline and incubated for one hour at 37'5° C. A control of antigen diluted 

 with saline was treated in the same fashion. After incubation the mixtures 

 were poured on hardened filter paper, and rapidly dried in vacuo. Previous 

 to use the paper was ruled by a platinum point into centimetre squares. The 

 results were not expected, and there further seemed to be a shade of 

 haemolysis hanging about certain squares that were not completely macerated. 

 The repetition with Serum 324 (Table V) was made in identical fashion, 

 except that the paper was thoroughly macerated before incubation. The 

 10 c.c. mixture, containing 1*5 c.c. serum, was spread over 40 squares (as in 

 the preceding) as evenly as possible. Squares for the test were taken 

 at random. It would seem that the negative attraction of antigen-inhibitive 

 serum mixtures is destroyed by rapidly drying. This contrasts not only 

 with parts of the work already given in Table III, but with the effect 



Table V.— Protocol 16.12.10. 







Hsemolysis. 



Paper thoroughly macerated 

 and incubated for 1 hour 



2 units complement (0 '5 c.c), 

 1 hour at 37 -5° C. 





S. 324— 



1 square in 1 - c.c. saline 



2 units complement (0 '5 c.c), 

 1 hour at 37 -5° C. 



Complete. 



2 



4 » 

 6 





None! 



Antigen only — 



1 square in 1 '0 c.c. saline 



2 units complement (0 "5 c.c), 

 1 hour at 37 -o' J C. 



Complete. 



2 

 4 

 6 







Untreated filter paper — 

 1 square in 1 "0 c.c. saline 



2 units complement (0 5 c.c), 

 1 hour at 37 "5° C. 



Complete. 



2 



4 „ „ 

 6 







Salt 1 -0 c.c. Complement -5 c.c. 

 „ 1 c.c. „ -25 c.c. 



Complete. 



In Tables 4 and 5, 2 hours' incubation were given after the addition of corpuscles and 

 hemolysin. 



