"The writings of those who have made the history and development of international usages a subject of special study will always constitute our chief source of knowledge upon the subject. The earlier writers were roughly grouped into two schools. One, made up chiefly of Continental authors, who were familiar with the Roman law, and by whom great authority was attached to the views of text writers. The other, composed of English and American writers, whose works, strongly influenced by the common law of England, attach the greatest weight to the decisions of competent courts and to the precedents established by the usages of nations and recognized by them as binding in their intercourse with each other. The present tendency is to obliterate this distinction. The history of both the Roman and common law has been exhaustively studied, and is now generally known, and the historical method of treatment is found to be as successful in its application to international as to municipal law.

17 Bradley J., in New York Life Ins. Co. vs. Hendren, 92 U. S., 288.

"A decided unanimity of opinion among authors as to the reason or justice of a particular usage is strong evidence of its general acceptance as a rule of international law. 'Writers on international law, however, cannot make the law. To be binding the law must have received the assent of the nations who are to be bound by it.' "18 19

18 Davis on International Law, pages 26 - 7.

19 For a convenient list of the prominent writers on this subject, see Wilson & Tucker on International Law, Sec. 13.