befriend and guide him. He attended the lectures on botany, zoölogy, mineralogy, physics, and anatomy, and began during the winter to perform dissections. But chemistry continued to be his favorite study, and, much to the disgust of his landlord, he transformed his parlor into a laboratory, and occupied himself with the study of sulphocyanic acid and cyanogen compounds in general. He discovered iodide of cyanogen, for to him at least it was a discovery, as he was not aware at the time that Davy had previously prepared it. In the joy of his heart he communicated the discovery to Wurzer, the Professor of Chemistry at Marburg, to whom it was also new, but, instead of receiving commendation, he was reprimanded for neglecting his medical studies to carry on original investigations. After spending one year at Marburg, Wöhler went to Heidelberg, filled with enthusiasm for Leopold Gmelin, who became his most cherished friend and master. He wished to attend Gmelin's lectures on chemistry, but was told by that professor that it was superfluous, and he accordingly abandoned the idea, and thus secured more time for work in Gmelin's laboratory and for intimate personal intercourse with this amiable and learned man.
Nearly all the time which his medical studies left him he devoted to chemistry, and even toward the close of his course, when practical medicine became very absorbing, he still continued to spend several hours daily in the laboratory. He resumed his researches on sulphocyanic acid at Heidelberg, and commenced those on cyanic acid, the results of which, at Gmelin's solicitation, were published in Gilbert's “Annalen.” It was of great service to Wöhler at this time that Gmelin and Tiedemann were engaged upon their physiological researches, thus encouraging him to a similar line of study. He enjoyed to a high degree the esteem of Tiedemann, and owes to this excellent man the kind encouragement to pursue physiological researches, which proved so important in Wöhler's future career. Wöhler was one of the competitors for the prize offered by the medical faculty for a thesis on the “Migration of Matter into Urine,” and had the good fortune to be successful. Among other things, it was shown by this research that plant-alkalies, in their transformation through the blood, are changed into carbonates. In September, 1823, Wöhler passed the university examination, and received the degree of Doctor of Medicine and Surgery, “nec non artis obstetriciæ.”
Immediately after leaving the University of Heidelberg it was Wöhler's intention to visit the larger hospitals of Europe, as a further preparation for the practice of his profession, but Gmelin advised him to abandon the uncertain practice of medicine and to devote himself solely to chemistry, for which specialty he had shown such decided inclination and talent. Acting upon this advice, Wöhler wrote to Berzelius for permission to study in the laboratory at Stockholm, and received from the great Swedish chemist the following answer: “Any
