During Müller's second year of medical study the University of Bonn announced its first prize, which was to be given for an investigation of the subject of respiration in the foetus. Although Müller was only in his first year as a medical student at the time, he grappled with the difficult subject and devoted all his spare time to arranging experiments for the demonstration and investigation of doubtful points. He received the prize, and Virchow, surely a good judge in the matter, says that this work of his student days is distinguished alike by the extent of its learning and by the number and boldness of the experiments detailed. At the moment of his graduation, the young doctor, in his twenty-first year, was already a marked man. From this time on everything that he did attracted attention and had a ready audience. Müller's mind was constantly occupied after this time with the arranging of experiments to demonstrate natural principles. How far he carried this habit of experimenting can be understood from some of the habits of control over {229} his muscles which he had acquired by continual practice and intense attention. He had thorough control over the muscles of his ears and used often to amuse his fellow-students by their movements. The anterior and posterior muscular portions of this occipito-frontalis muscle were able readily to move his scalp and produce curious disturbances in his hair. These habits of muscular control many people have acquired. Other acquisitions of Müller's are, however, much rarer. He could, at will, contract or dilate his pupils, having secured control over his iris by practice before a mirror, and he could use the little muscles that connect the bones within the ear, the hammer, anvil and stirrup, so as to make them produce an audible click at will. His habits of experimentation on one occasion at least placed him in a rather ridiculous position. While making his military service, it happened one day that when the command "Order arms" was given, Müller amused himself by inserting one finger after another into the muzzle of his firelock. At last his middle finger got fairly wedged into the weapon. When the order attention was given, Müller could not withdraw his finger. His predicament at once attracted notice, and he was ordered to the front to be reprimanded by the major, to the no small amusement of his comrades, who laughed heartily at his ridiculous predicament. He was sent to his quarters in disgrace and the regimental surgeon had no little trouble in liberating the thickly swollen finger.