The students of all the colleges in the country must unite in condemning the action of the person or persons who recently sent marked copies of the New York Tribune, containing a personal attack upon a popular professor, to the students of Yale College. Such interference is in the highest degree impudent and underhanded. It is not at all a question of free trade or protection which is involved. The case is one of the greatest concern to all college men, as it strikes directly at the right of instructors to teach in the way that seems best to them. However disagreeable the teachings of a professor may seem to any set of men, it is absolutely necessary that the professor should be sustained in his right to present what appears to him the true principles of his subject. The advocates of protection have certainly weakened their falling cause by the adoption of such disgraceful weapons as the personal attack on Professor Sumner. There is no doubt that all college students will support the instructor against the malicious attacks of a few fanatics.