It was an unlucky day for medicine, which is human biology, which depends on cell specificity, when the word immunology was invented. Soon the word came to mean a thing. The many and diverse protective reactions of the billions of billions of cells in the body came to be included under a single word. The well-meaning but mischievous biologists who hope life is chemistry and physics cheered when antibody was detected in the blood serum of immune patients.
Ackernecht has told us (Rudolf Virchow, 1953) how jealous von Behring was of Virchow and how he fought for humoralism against cellular pathology. Nobody needed to know how the chemical substances got into the blood. The fact that they were there was sufficient; this branch of medical science looked no longer at the cells but at the fluids in the body. Decades were spent in speculation on the nature of these chemical