:'>72 H. R. Seddon : 



It has been found very delicate, as little as 0.0025 c.c. of exud- 

 ate causing agglutination. From one of these positive cases the 

 blood serum, secured 16 days later than the exudate and 17 days 

 after abortion, gave an exactly similar agglutinating titre to the 

 exudate. (See Cow II., " Bluey.") 



Further, exudate may be kept until it is fairly swarming with 

 bacteria, and yet show little loss of agglutinant action. Also 

 exudate diluted with carbolised saline (10% of exudate in saline 

 containing 0.5% of carbolic acid) shows little loss of agglutinating 

 bodies. 



Exudate from a healthy cow which calved at the Institute was 

 tested, and even in an amount of 0.25 c.c, failed to give any 

 agglutination. 



5. Coinjdement Fixation Test. — No opportunity has presented 

 itself of applying this test to exudate, but, judging from the re- 

 sults with the agglutination test on this material, there seems to 

 be no reason why it should not be of use for diagnostic purposes. ^ 



Details of Cows. 



I. Normal Cow. — This animal was kept at the Institute in con- 

 nection with another experiment. She calved, after the usual signs 

 of on-coming parturition, the offspring being of full size, and 

 vigorous. 



Exudate secured the day she calved gave no agglutination with 

 0.25 c.c. 



Whey from milk taken eleven days after calving gave a positive 

 agglutination with 0.25 c.c, but a negative with 0.05 c.c. 



II. Cow, " Bluey." — Detailed history not available. Aborted 

 on 1st September, 1913. Exudate — in appearance typical of the 

 disease — was secured from the vagina next day. It Avas tested four 

 days later, and agglutinated at 0.15 c.c, this being the smallest 

 quantity used. Twelve days later the end-point was determined 

 to be 0.0025 c.c, the material used in this test having been left 

 in the bottle and being now fairly putrid. At the same liime 

 material which had been diluted with carbolised saline twelve days 

 ago now gave a reaction with 0.005 c.c 



Microscopical exainination of exudate showed long chains of 

 bacilli, streptococci, and also some clumps of bacilli the siae of B. 



1 An opportunity has since presented itself of testing:, by the Complement Fixation method, a 

 ''ample of vapinal exudate from a cow which had recently aborted. The result was positive, thus 

 showing- that tlie test may l)e .ilso availed of for diagnosis as is suggested al)ove. 



