Ludwig's disinterestedness toward his pupils went to such an extreme that he allowed works that had been accomplished under his immediate supervision—generally, in fact, executed by his own hand, and also, as a rule, prepared for editing by him—to go out into the world under the name of the pupil who had assisted him. He not only did this in the latter years of his life, as a world-renowned scientist, but as early as the time of his stay in Marburg, at an age and in a position in which young men are usually less generous with their names. Under the names of Mogk, Spengler, Becher, and others, Ludwig's youthful investigations went forth, and when in 1847 he published his invention, the kymographion, under his own name, he apologized for it, saying that his young friend Gerau, then otherwise engaged, should really have done this. And yet in this case it was the question of one of the most important discoveries in natural history, in view of its later consequences. Ludwig, by means of his kymographion, introduced the principle of self -registering apparatus into science—a principle the importance of which may well be compared with that of the microscope, for it was first by means of such apparatus working as time microscopes that it became possible to directly observe and comprehend rapid and complicated processes.
As with the pupils in his laboratory, Ludwig also associated with his students with friendly sympathy. They all felt this, and returned it with warm attachment and respect. They usually attended each of his lectures two or three times, as the beginners were hardly able to master the information they received at the first hearing. In especial physiological conferences Ludwig gave the students opportunity of talking with him personally. For my part, it was a continual source of astonishment to me to see how accurately Ludwig was informed with regard to the industry and talents of the individual students.
Ludwig's workroom was a place to which the most heterogeneous elements had free access—foreign scientists, colleagues of all the faculties, physicians, friends, and pupils. There one might at any time seek his advice and enjoy the magic of his society. With his many-sided and thorough education, and his ever quickly roused enthusiasm for all sorts of new problems and lines of work, it was easy to interest him in questions of the most varied character. His great knowledge of the world and of human nature made his conversation a never-ending source of interest and information. Ludwig's point of view was ever lofty; the lines of thought on which he worked were always original, never commonplace. With his subtle humor he would occasionally maintain a paradoxical opinion. If, however, he was opposed by arguments that were repugnant to his idealism,
