Laboratory workers who have dealt extensively with experiments in agglutination have felt doubt at times as to the reliability of a given reaction, away from the associated clinical findings. With the knowledge that the agglutination phenomenon is essentially a quantitative one, the question arises: Is the dilution of the serum too large for the feebly developed agglutinins; is it large enough to differentiate the specific agglutinins from the normal and from co-agglutinins or group agglutinins? This question of dilution becomes particularly important in cases of evident mixed infection.
While, with relatively high dilutions, the less strongly developed normal agglutinins and co-agglutinins are usually ruled out, there still remain a number of cases in which the results are decidedly at variance with the specific reaction with the ordinary laboratory technic, as is illustrated in the following case:
—Max M., laborer, aged 40, Hungarian, came to this country two years ago.