1908. | Hem-agglutinins, etc., in the Blood. | 537 
pneumonia, on which these saturation experiments were made, have been 
referred to already in detail. The immune serum, when added to normal red 
cells, caused a high degree of agglutination. When saturation was completed, 
it was found that the resulting clear fluid failed to agglutinate normal red 
cells, but still had the power of agglutinating the red cells from a case of 
epilepsy, although to a less extent than previous to saturation with normal 
red cells. Normal serum and the pneumonic red cells, when mixed together, 
caused a high degree of clumping to occur. The clear fluid which resulted 
from the saturation of this sample of immune red cells and normal serum 
would not react with the immune red cells, with which excessive clumping 
had occurred previous to saturation. 
The serum from another case of acute pneumonia, just after the crisis, 
failed to react with the immune red cells or with normal red cells, but normal 
serum, when added to these immune red cells, produced a high degree of 
clumping. The examination of the blood in this instance is, therefore, of 
considerable interest, because the immune serum had no agglutinative effect 
ou either immune or normal red cells, but normal serum which had no 
clumping action on normal red cells and on certain other examples of immune 
red cells, yet produced enormous clumping in the presence of the pneumonic 
red cells. When normal serum was saturated with these immune red cells, 
the clear fluid that resulted failed to agglutinate them, but produced some 
degree of agglutination in the presence of a sample of tuberculous red cells 
which had given considerable clumping with the normal serum previous to 
agelutination. When the normal serum and tuberculous red cells were 
mixed together and saturation was completed, the clear fluid obtained would 
not agglutinate the pneumococcal red cells referred to above or the tuber- 
culous red cells. The immune serum from a case of severe pernicious anemia 
and the same specimen of tuberculous red cells showed considerable clumping 
when brought into contact. When saturation was completed, the resulting 
clear fluid failed to agglutimate either the tuberculous red cells or the 
pneumonic red cells which had run together in large masses in the presence 
of the serum from this case of pernicious anzemia previous to saturation. The 
last series of experiments completed in this group of specific agglutinative 
tests are of importance, because they illustrate the fact that saturation of the 
pernicious anemia serum with normal red cells, with which it failed to react 
previous to saturation, had no power to remove the agglutinative property 
from this sample of immune serum either for the tuberculous or the pneu- 
monic red cells. In this special instance the agglutination was as well marked 
after as before saturation. 
