(a) Witnesses shall be allowed $1.50 per day in civil cases; also, $.05 per mile for each mile to and from their residence by the usual traveled route and all necessary ferriage, tolls of turnpikes and toll bridges, whether attending under subpoena or at the request of the party.
(b) A witness shall charge for his mileage and attendance but on one side of the same case, and a witness attending in more cases than one at the same time shall only be entitled to a fee in one case, to be selected by him while so attending; but if, after the case in which he elects to claim his fees is disposed of, his attendance is required in the other case or cases, he shall for such attendance be entitled to claim his per diem in such other case or, if more than one, in the one which he may elect to claim his fees, and so on, until all the cases in which he is required to attend are disposed of by trial, continuance or otherwise; but no witness shall receive his per diem in more than one case for the same day.