Dr. Roloff, head of the Veterinary School of Berlin, hastened to take the initiative, by an application to the German Minister of Agriculture. The minister at once nominated a Commission to follow the experiments in vaccination and to draw up a report for the German Government. M. Pasteur entrusted the conduct of the vaccinations to his new colleague, Louis Thuillier, who accepted with deep and silent joy the management of an experiment that was to test a French discovery. He was always ready for anything, this brave Thuillier, who was destined to die, a martyr to the cause of science, in the full promise of his youth, and in the full hope of glory. His courage and his work were alike great and silent. In the laboratory he would spend days, even weeks, without speaking, bent over his microscope with tenacious resolution, endeavouring to follow Pasteur in all his investigations: proud to live near his illustrious master, happy to be his disciple and to be loved by him almost as a son. What a vacancy he has left in the laboratory! What a place he might have held in science! The composition of the German Commission, over which M. Beyer, member of the Superior Council of Government, presided, showed clearly the importance attached by Germany to the investigation of this French discovery. Among its members was the famous Professor Virchow. The experiments were carried out on the estate of Pakisch. The minutes and reports of the Commission left no doubt as to the correctness of the facts announced by Pasteur. But, as the negations of Dr. Koch and his colleagues embraced questions beyond that of the prophylaxy of splenic fever, Pasteur did not rest content with this initial success; he sought for a fresh opportunity of convincing his opponents. This opportunity occurred in September 1882, when an International Hygienic Congress was held at Geneva. Thither went Pasteur, hoping to meet Dr. Koch at the sittings; and he was not disappointed. Dr. Koch was there, surrounded by his disciples. From the tribune of the Congress, Pasteur refuted his criticism, exposed his errors, and challenged him to a discussion in the presence of competent judges. There was an instantaneous salvo of applause, and everyone awaited Dr. Koch's reply. But he declined all debate, reserving his case for careful and deliberate statement in the press. It took three months for Dr. Koch to bring out a small pamphlet, and these three months had borne their fruit. The discovery of the attenuation of virus, which had been so vehemently attacked only a year before in the report of the Sanitary Office, was now extolled by Dr. Koch as a discovery of the first importance. Being, however, unwilling absolutely to stultify himself, he continued the attack by denying its efficacy in practical agriculture. * * * * * The clear, direct style of argument, which goes straight to its point, was invariably adopted by Pasteur.