52 OHNO. 



of salt solution. This great viscosity causes the depression of the phe- 

 nomena of agglutination. The grade of depression, plotted in the 

 coordinate system, is approximately expressed by the formula, 

 2/ 2 =4 ~Kjb. 



the equation of a parabolic curve, where y is the degree of depression; x 

 the quantity of serum in the test tube, and K is a constant, which varies 

 according to the type of serum as follows: 



K with the serum of 



206.5 rabbit 



233.5 calf 



345.8 horse 



367.0 cow 



where y=100 (to express the percentage of depression of agglutination 

 with a certain quantity of united agglutinin) and x=l (taking 2 cubic 

 centimeters of serum in a test tube as the unit). In consideration of 

 this fact, it seems that we need to correct the values of agglutinin and 

 agglutinoid from the formula 



G 771 



A = CM 

 B = Cm 



M — m 



M — G 



M — m 



because the value of m is somewhat smaller than it should be, but prac- 

 tically we need not make such a correction because the difference is so 

 very slight that we can neglect it in calculation, it (8) being expressed 

 by the equation 



where D is the reciprocal of serum dilution jy while the value of 



K varies from 14 to 30. Therefore, the value of 8 is approximately 0.84, 

 at the maximum, when M=10. When M=10,000 the value of 8 is 

 0.004 and so on. In estimating the grade of agglutination, on the other 

 hand, we must correct by adding the difference, because this quantity 

 is greatly influenced by even such a slight amount. When we correct 

 the quantity of united agglutinin by adding the difference, we obtain 

 agreement between the calculated grades of agglutination in loth ante- 

 and post-phase, in cases in which the same quantity of agglutinin is 

 united and this supports the theory that agglutinin always combines with 

 agglutinable substance in a constant ratio and demonstrates the influence 

 of serum viscosity upon agglutination. 



While at the post-phase of agglutination the total quantity of agglu- 

 tinin is absorbed (united) by the agglutinable substance, during the- 



