Release of Rev. Mr. Gibson, of Baltimore.
--The imprisonment and subsequent release of Rev. Mr. Gibson, of Baltimore, by the Federal authorities there, has been noticed. The following is a copy of the letter which caused his arrest:
--Your favor of the 21st instant reached me last evening. I should be most happy to receive your son, but think it only proper to inform you that in the unhappy differences which now distract the country all my pupils this year, without exception, advocate the Southern side. In view of this, I fear your son would not find it pleasant here.