concurring specially. At the former appearance of this case the writer dissented, because he was of the opinion that under the ruling in Linton v. Lucy Cobb Institute, 117 Ga. 678 (45 S. E. 53), the function of Oglethorpe University in carrying on a branch of education by means of radio, from which no profit was derived, exempted it from taxation under the constitutional provisions upon that subject. However, I agree that the former decision between the same parties fixed the law of the case, and that the judgment in this case is absolutely controlled by the prior ruling of this court.