Complex sentence: Sollogub was a connoisseur of theatrical life and of St. Petersburg society, in which he hosted a well-known literary and musical salon; he brought to life the atmosphere of St. Petersburg of that era in his "Memoirs" (1887).
Split into simpler sentences: Sollogub was a connoisseur of theatrical life and of St. Petersburg society. He he hosted a well-known literary and musical salon where he brought to life the atmosphere of St. Petersburg of that era as related in his "Memoirs" (1887).