sometimes accompany ability of the highest order. As a student, Ehrlich bore out President Eliot's theory that any young man who has real capacity usually has a better inkling of its extent, if not of its limitations, than his elders can teach him. Age and experience may perhaps indicate what youth can't do, but they have no power of predicting what it can do. It is related that when Robert Koch was once visiting the Breslau laboratories, a young student working at a table covered with staining materials was pointed out to him, with the remark: "There is our little Ehrlich. He is a first-rate stainer of tissues, but he will never pass his examinations." The prediction was true. Ehrlich got his degree by courtesy, on the strength of his well-known discoveries in the histology of the blood; but doubtless his academic sponsors serenely followed the example of Kant, who, in lecturing, addressed himself to students of mean average intellect only, on the assumption that the blockheads were beyond human help, while the geniuses could take care of themselves. The young Ehrlich easily made himself recognized as a true-born scientific genius, but his example will scarcely save less careful or more luckless students from being plucked at their final examinations.
Although for practical use, Ehrlich's researches in synthetic chemistry rank near to those of Emil Fischer, he is a true Asclepiad, and his principal aim has always been to improve the diagnosis and treatment of disease. Nearly all his results are of fundamental importance for actual medicine and they are a long list. We can imagine some awarder of a Copley medal or Nobel prize recounting them: First, the improved methods of drying and fixing blood smears by heat and the staining methods which have become such a feature in recent diagnosis, notably the tri-acid stain, the fuchsine stain for tubercle bacilli and the method of intra-vital staining, the first step towards getting in touch with what is going on inside the living cell; then his discovery of five new constituents of the blood which have become basic principles in modern diagnosis; his important study of the oxygen requirements of a living organism; his diazo-test for the urine in typhoid fever; his demonstration that animals can be quantitatively immunized against the effects of vegetable poisons like abrin and ricin, as well as against the toxins of vegetable parasites; and conversely, that animal parasites have the power of immunizing themselves and their descendants against the action of drugs; his improvement of Behring's diphtheria antitoxin and his establishment of an international standard of purity for the same; his side chain theory of immunity, which led at once to such brilliant results as the Wassermann method of serodiagnosis and (in medical jurisprudence) to the precipitin tests for blood-stains (Bordet-Uhlenhuth) and the cobra-venom test for insanity (Much-Holtzmann);
- The anecdote is given by the late Dr. Christian A. Herter in Jour. Am. Med. Assoc, Chicago, 1910, LIV., 428.