BAHAI LEADER IN LONDON. The “Christian Commonwealth” announces that Abdul Baha (Abbas Effendi), the leader of the Bahai movement, has arrived in London. He expects to remain about a fortnight in this country. Abbas Effendi is a son, and the generally recognized successor, of Mirza Hussein Ali, the so-called Baha-Ullah ( the “Splendour of God “), the founder of the larger, or Bahai, section of the Babi sect. Mirza Hussein Ali, an elder brother of Subh-i-Ezel (” the Dawn of Eternity “), who succeeded the Bab after his martyrdom at Tabriz in 1850, proclaimed himself, in 1863, to be the prophet whose advent was announced by the Bab, and was acknowledged as such by the majority of the sect.