538 Mr. L. 8. Dudgeon. On the Presence of [July 31, 
Bacterial- and Hem-agglutinins present in the same Serum. 
The serum obtained from a case of typhoid infection was found to possess 
a very high degree of agglutination on normal red cells, but did not possess 
any auto-agglutinative properties. When the patient’s serum was saturated 
with his own red cells, it was found that it still possessed as high a degree of 
agglutination on typhoid bacilli as before saturation. The same serum when 
saturated with normal red cells, on which it had a marked ageglutinative 
action, still possessed the same power of clumping typhoid bacilli as in the 
previous experiments. A further experiment was performed with the serum 
from another case of typhoid fever. Saturation of this serum, which had 
caused marked agglutination when added to typhoid bacilli and normal red 
blood corpuscles, removed the agglutinative action on the red cells, yet it had 
no effect on the clumping action of the bacill.* 
The Relationship between Rouleaux Formation and Agglutination of the Red 
Blood Corpuscles. 
In normal blood rouleaux formation is a constant factor. In certain acute 
and chronic diseases the rouleaux formation is either present to a slight 
degree or is absent. In those cases in which its absence is noted, it may be 
found that agglutination of the red cells is present instead. It will be seen, 
however, from previous statements, that auto-agglutination is of rare 
occurrence, while iso-agglutination of one type or other is extremely common. 
It is, therefore, not strictly accurate to state that agglutination of the red 
blood corpuscles in certain diseases replaces or has replaced the rouleaux 
formation which was present in that same blood in health, because rouleaux 
formation, as we see it, is a true auto-effect—the red cells and the plasma 
irom the same case. In agglutination it is generally otherwise, that is to 
say, the clumping of normal red cells in the presence of immune serum or 
vice versd is an iso-effect. True agglutination, such as may be seen in the 
experiments which I have referred to, is never to be found ino blood obtained 
directly from the patient. Agglutination of the rouleaux may take place in 
pathological blood; in some diseases ié is very obvious, but here again the 
small clumps of rouleaux do not resemble actual agglutination of the red 
blood corpuscles. In a paper on acute lymphocythemia, which I published a 
few years back in the ‘Transactions of the Pathological Society of London, 
attention was drawn to agglutination of the red cells in the fresh blood 
* In this communication only a few of the experiments on specific and simple 
hem-agglutinins have been referred to, as it would be unnecessary repetition to cite 
them all. 
