536 Mr. L. 8. Dudgeon. On the Presence of [July 31, 
Specific Hem-agglutinins. 
In these experiments, if a serum was found to produce marked agelutina- 
tion when mixed with certain red blood corpuscles in the manner described, 
it was tested for the presence of specific agglutinins. A definite measured 
volume of the immune serum was mixed with a similar volume of a thick 
deposit of the washed red cells obtained at the end of the last stage of 
centrifugalisation. These red cells were not suspended in saline, so that the 
serum could be more intimately mixed with a dense volume of red cells, and 
would not be diluted with salt solution. The mixture was incubated in 
sealed capillary tubes for several hours at 37° C. It was then centrifuged at 
high speed, and the clear serum tested on a 5-per-cent. suspension of washed 
red cells as before. 
The first case in which the specific effect may be referred to is one of great 
interest. The immune serum from a case of acute pulmonary tuberculosis 
was found to produce a high degree of agglutination when mixed with the 
red blood corpuscles obtained from a case of anesthetic leprosy, and with 
normal red cells, but there was absence of any auto-agglutination. The 
serum from this case was “saturated ” with the red blood corpuscles (leprosy) 
in the manner referred to in the technique. The mixture, after incubation, 
was centrifuged, and the clear fluid which separated was added to the leprosy 
red cells and to normal red cells. No agglutination resulted. When the 
immune serum was saturated in a similar manner with the normal red cells, 
the clear fluid obtained did not agglutinate normal red cells, and only slight 
agglutination occurred when it was added to the leprosy red cells. The serum 
from a case of chronic surgical tuberculosis which had been found to produce a 
high degree of agglutination when added to normal red celis and the leprous 
red cells, although it failed to show any auto-agglutination, was saturated 
with normal red cells. The clear fluid was then added to normal red 
cells, but no agglutination resulted. When added, however, to the leprous 
red cells, distinct agglutination occurred. From these experiments, it 
would seem that the leprous red cells had the power of removing entirely the 
ageglutinative properties of the serum from the case of acute pulmonary 
tuberculosis ; this serum, as the result of saturation, failing to agglutinate 
either the leprous red cells or the normal red cells. When, however, the 
serum from the case of acute pulmonary tuberculosis, and from the case of 
surgical tuberculosis, was saturated with normal red cells, the result was to 
abolish the clumping action with the normal red blood corpuscles, but to 
leave a certain degree of agglutination for the red cells of the leper. 
The simple aggiutinative properties of the blood from the case of acute 
