Vertigo, it was thought at the time, could only be caused by a disease of the cerebellum. He observed this kind of patient for years and saw absolutely no symptoms of brain disease.

Even such an obvious idea as to observe an animal with vertigo or to rotate an animal did not occur to him, in spite of the fact that he conducted numerous vertigo experiments with human subjects and made frequent use of animal experiments.

Two minutes later the right arm was pointing normally and the reaction to the left appeared. The patient made no complaint at all about the experiment.

Only the madman is absolutely sure.

The incorrectness and weaknesses of a theory cause other minds to formulate the problems more exactly and in this way scientific progress is made.

The investigations also proved that there were many cases of spontaneous deviation, i.e. cases where there had been no stimulation of the semi-circular canal apparatus.