534 Mr. L. 8. Dudgeon. On the Presence of [July 31, 
subject in human hematology, he always employed normal human blood and 
added to it the wmmune serum. The importance of this detail will be referred 
to later. 
In 1900, Griinbaum* read a preliminary report which was published in the 
‘ British Medical Journal’ on the agglutination of red blood corpuscles. He 
came to the following conclusion as the result of his preliminary investi- 
gations: “ While the serum from a case of typhoid would clump the corpuscles 
in the blood from another disease, it did not clump the corpuscles from the 
same disease. The same held good for scarlet fever.” 
It appears from the investigations which I have made that it is extremely 
common to obtain agglutination by allowing normal serum and immune red 
cells, or normal red cells and immune serum, to interact. In every instance 
a control experiment was also made by employing normal serum and normal 
red cells. Agglutination was not observed when normal serum was added to 
normal red cells, either of the same individual or from another healthy 
person, with one exception—a serum from an apparently healthy medical 
student working in my laboratory caused marked agglutination of my red 
cells. There was no auto-agglutination observed in this instance, and no 
other normal serum agglutinated either my red cells or his red cells. 
The class of cases in which agglutination is most commonly met with 
appears to be patients suffering from tuberculosis. In this disease agglutina- 
tion of human red corpuscles by one of the methods already referred to 
is a matter of common occurrence. In these cases examples of 1iso- 
agglutination have been obtained, and also the still rarer phenomenon of 
auto-agelutination. This can be very well shown in an experiment which 
was conducted with the red blood cells and the serum obtained from a very 
severe case of pulmonary tuberculosis :— 
| 
| N 0. | Equal volumes of— Result. 
| 
| 
1 Immune serum (tuberculous) and normal red cells ...| Pronounced agglutination was 
obtained (iso-agglutination). 
Li e2 Immune serum (tuberculous) and immune red cells | Similar result (auto-agglutina- 
(tuberculous) tion). 
| 38 Immune serum (tuberculous) and immune red cells | Same result (iso-agglutination). 
| (epilepsy) 
| 4 Normal serum and normal red cells ...,...........sseseeee No agglutination. 
5 Normal serum and immune red cells (tuberculous) ...| Good agglutination (iso-agglu- 
tination). 
The blood obtained from a case of chronic pulmonary tuberculosis gave 
a result which is commonly met with. The immune serum caused a high 
* A.S, F. Griinbaum, ‘ British Medical Journal,’ 1900, vol. 1, p. 1089. 
