Agglutination Test in Abortion. 387 



Here, again, there being no universal standard adopted, ob- 

 servers cannot strictly compare their results. Thus, to say that 

 an animal, 0.05 c.c. of whose serum produces agglutination, should 

 be considered as affected, in reality conveys no definite meaning, in 

 view of the experiments in sub-sections (a) and (b) above, unless 

 the amount of emulsion be stated at the same time. On the other 

 hand, workers find by experience what is a convenient quantity of 

 emulsion to use, based on the size of the tubes employed, etc., and 

 having found this amount retain it as a standard and use this in 

 future; their own results, therefore, are strictly comparable with 

 one another, but not with those of other workers. 



The following experiments were made to determine what quan- 

 tity, allowing for ease of reading after 24 houis' incubation, was 

 suitable to use. 



Material. 



Serum, from Cow (as used in previous tests). 



Emulsion (standardised, = " 10 X "). 



Four sets of tubes, numbered 1, 2, ?>, 4, were put up, iising a 

 different quantity of serum in each set. Eacli .set consisted of four 

 tubes — A. B, C, and D, and the quantity of emulsion used was: — 



in the A tubes - 0.05 c.c. (10 X emulsions) 



,. „ B „ - 0.025 c.c. 



.. „ C „ - 0.01 c.c. 



„ „ D „ - 0.005 c.c. 



To Set I. was added 1 c.c. diluted serum (equal to 0.02 c.c. pure 

 serum), and carbolised saline was added, to make tlie Total Vol. 

 2 c.c. 



To Set II. was added 0.5 c.c. diluted serum (wjual to 0.01 c.c. 

 pure serum), and carbolised saline Avas added, to make the Total 

 Vol. 2 c.c. 



To Set III. was added 0.25 c.c. diluted serum (equal to 0.005 c.c. 

 pure serum), and carbolised saline was added, to make the Total 

 Vol. 2 c.c. 



To Set IV. was added 1 c.c. diluted serum (equal to 0.02 c.c. 

 of pure serum), and carbolised saline was added, to make the Tf)tal 

 Vol. 20 c.c. 



Controls. — Serum controls were put up. and remained unchanged. 



Emulsion control tubes, of each quantity of enuilsion used, with 

 •carbolised saline added, were put up, and remained unchanged. 



Sets I., II., and III. Avere read at the end of 24 hours' incuba- 

 tion, the result ]>eing : — 



