The new period which now begins was introduced by some alterations in the official organization. Hitherto almost the whole of the internal business had been concentrated in the imperial chancery (_Reichskanzleramt_), and Bismarck had allowed great freedom of action to Delbrück, the head of the office. Delbrück, however, had resigned in 1876, justly foreseeing that a change of policy was imminent in which he could no longer co-operate with Bismarck. The work of the office was then divided between several departments, at the head of each of which was placed a separate official, the most important receiving the title of secretary of state. Bismarck, as always, refused to appoint ministers directly responsible either to the emperor or to parliament; the new officials in no way formed a collegiate ministry or cabinet. He still retained in his own hands, as sole responsible minister, the ultimate control over the whole imperial administration. The more important secretaries of state, however, are political officials, who are practically almost solely responsible for their department; they sit in the Bundesrat, and defend their policy in the Reichstag, and they often have a seat in the Prussian ministry. Moreover, a law of 1878, the occasion of which was Bismarck's long absence from Berlin, empowered the chancellor to appoint a substitute or representative (_Stellvertreter_) either for the whole duties of his office or for the affairs of a particular department. The signature of a man who holds this position gives legal validity to the acts of the emperor. This reorganization was a sign of the great increase of work which had already begun to fall on the imperial authorities, and was a necessary step towards the further duties which Bismarck intended to impose upon them. Meanwhile the relations with the National Liberals reached a crisis. Bismarck remained in retirement at Varzin for nearly a year; before he returned to Berlin, at the end of 1877, he was visited by Bennigsen, and the Liberal leader was offered the post of vice-president of the Prussian ministry and vice-president of the Bundesrat. The negotiations broke down, apparently because Bennigsen refused to accept office unless he received a guarantee that the constitutional rights of the Reichstag should be respected, and unless two other members of the party, Forckenbeck and Stauffenberg, were given office. Bismarck would not assent to these conditions, and, even if he had been willing to do so, could hardly have overcome the prejudices of the emperor. On the other hand, Bennigsen refused to accept Bismarck's proposal for a state monopoly of tobacco. From the beginning the negotiations were indeed doomed to failure, for what Bismarck appears to have aimed at was to detach Bennigsen from the rest of his party and win his support for an anti-Liberal policy. Period after 1878.