1908. ] Hem-agglutinins, etc., in the Blood. 543 
instance occurred in the case of a girl suffering from acute poisoning of 
unknown origin. Here, although immune serum failed to hemolyse the 
immune red cell, yet physiological salt solution produced slight hemolysis 
when presented in the same amount as the serum in the hemolytic mixture, 
while, when present greatly in excess of the serum, marked hemolysis 
occurred. 
In all these experiments it was only occasionally that the hemolytic action 
was distinctly shown ; in the majority of instances no hemolysis occurred. 
In Group I—cases of pneumonia—there were two instances in which 
hemolysis occurred. The first example was a case of acute pneumonia, just 
before the crisis, in which a mixture containing 75 per cent. of auto-immune 
serum produced complete hemolysis on auto-immune red cells. The 
hemolytic action occurred down to a dilution in which the serum was 
present to the extent of 25 per cent. 
The second example was a case of acute pneumonia, just after the crisis, 
and in this instance the immune serum hemolysed normal red cells, but 
failed to hemolyse the auto-immune red cells. Well-marked hemolysis 
occurred with 75 per cent. of serum. On diminishing the amount of serum, 
the effect became less until 37°5 per cent. of serum caused only a very slight 
hemolytic action. 
In Group J[—cases of tuberculosis—hemolysis was only occasionally met 
with. In each instance it was the action of the immune serum obtained from 
cases of acute pulmonary tuberculosis on normal red cells. In these experi- 
ments the hemolysis was well marked, while auto-hemolysis did not occur. 
In Group VI—pernicious anemia. All the cases referred to under this 
heading were well-marked examples of the disease. It may be of interest 
to mention that out of the several cases which were examined, in every 
instance the serum was either bile-tinged or more frequently of a canary- 
yellow colour, due to the presence of a pigment which failed to give any 
spectrum, and which was not bile-pigment. In most of these cases neither 
auto- nor iso-hemolysis occurred. 
In one case extremely slight hemolysis occurred by the action of immune 
serum on normal red cells, while there was no auto-hemolysis. 
In another case there was no hemolysis during the patient’s lifetime, but 
the serum obtained at the post-mortem examination, which contained bile- 
pigment, was found to have a very strong hemolytic action on normal red 
cells; 75 per cent. of serum almost completely heemolysed the red blood 
corpuscles, while 12°5 per cent. of serum produced distinct but slight hemo- 
lysis. It was found that in each tube in which hemolysis occurred, clumps 
of streptococci were present. This streptococcus, which was obtained in pure 
