When some more than ordinarily independent student would come whispering to him that he had discovered a remarkable something about blood, Metchnikoff became magnificent like Moses coming down off Mt. Sinai--searchers for mere truth had a bad time in that laboratory, and you can imagine the great dauntless champion of phagocytes ordering a dissenter from his theory to be burned, and then weeping inconsolably over him afterwards. But, just the same, Metchnikoff--so great was the number of experiments made by an always changing crowd of eager experimenters in his laboratory--this Metchnikoff was partly responsible for the discovery of some of the most astounding virtues of blood. For, in the midst of his triumphs, Jules Bordet came to work with the master. This Bordet was the son of the schoolmaster of the village of Soignies in Belgium. He was timid, he seemed insignificant, he had careless ways and watery-blue, absent-minded eyes--eyes that saw things nobody else was looking for. Bordet set to work there, and right in the shadow of the master’s beard, while the walls shook with the slogan “Phagocytes!”--the Belgian pried into the mystery of how blood kills germs; he laid the foundation for those astounding delicate tests which tell whether blood is human blood, in murder cases. It was here too, that Bordet began the work which led, years later, to the famous blood test for syphilis--the Wassermann reaction. Metchnikoff was often annoyed with Bordet, but he was proud of him too, and whenever Bordet found anything in blood that was harmful to microbes, and might help to make people immune to them, Metchnikoff consoled himself by inventing more or less accurate experiments which showed that these microbe-killing things came from the phagocytes, after all. Bordet did not remain long in Metchnikoff’s laboratory....