on 8 december 1869, he took part in the inauguration of the œcumenical council of the vatican. on 17 april 1870, he was named by pope pius ix one of the bishops assistant at the pontifical throne. some weeks before the declaration of the dogma of papal infallibility, on 18 july 1870, brown was released from his attendance upon it on the score of ill-health, and received permission to return homewards.