494 Captain A. G. McKendrick. [ Nov. 30, 
opposed to complement plus catalyst action—not a direct opposition in the 
fluid, but an opposition in their action on the cell. 
Y 
—z = concentration of free amboceptor, 
2 ? 
——z = concentration of free complement, 
Cb 
concentration of amboceptor, both free and combined (1.e. the con- 
centration in which it acts catalytically). 
Uh ae 
C 
The fundamental equation (1) was obtained from a study of the value 
of z got by mixing varying proportions of y and 2. 
The details of experiment are as follows :—The materials used were human 
serum for the serum components, and the cells were washed horse cells. 
Three fluids were made up :— 
Unheated serum. Heated serum. 4.6. Y L. 
| parts. parts. 
aid der MER Roe eee enenG ! + 0 4 4 
aj.» WD saehoput stan Sacer ee 2 2 4, 2 
50) Obaticimiqaeeemtreneccerias | I 3 L 1 
A series of dilutions of each of these fluids was put up as follows :— 
Fluid a, b, orc. — Visio Jena, ION Washed cells. 1G eee 
solution. amboceptor. 
c.c. | c.c. c.c. 
1 2°45 0-0 0-05 98 ‘0 
2 2 ‘05 0 *4, 0-05 82 0 
3 1°8 0°65 0-05 | 72°0 
4 1°55 0°9 0°05 62 °0 
5 1°3 1°15 0-05 52 °0 
6 1°05 1 °4 0°05 42 °O 
7 0°8 1°65 0 05 32 ‘0 
8 0°55 1°9 0 05 22 °0 
9 0°5 1 ‘95 0°05 20.°0 
10 0-44 2°01 0 05 176 
il 0 °375 2 065 0-05 15°0 
12 0°31 2°14 0-05 12 °5 
13 0°25 2°2 0-05 10-0 
14 0 ‘187 2 °263 0°05 7:5 
15 Or25) 2 °325 0:05 5 °0 
| 16 0 0625 2 °3875 0°05 Pe 
Ly 0-0 2°45 0-05 0-0 
I used this arrangement of combinations of heated and unheated sera 
because by it the area in which the phenomenon of diversion occurs, whose 
characteristics I had set out particularly to investigate, can be explored and. 
