The supreme importance of the Rig-veda in all questions bearing on the history of the Aryan mind, and on the development of the religious idea in man, gives interest to every attempt to throw light on that priceless heir-loom of India. Much has already been done by able scholars, in many ways, to investigate the language and ideas enshrined in the Rig-veda-sanhitâ; but no one has yet discovered the principle on which the hymns are arranged among themselves, or has advanced beyond the mere consciousness expressed by Prof. Max Müller in his History of Ancient Sanskrit Literature, that “there is some system,” “some priestly influence,” “traces of one superintending spirit,” and such-like generalities. The object of the following paper is to show the principle which regulated the formation of the Sanhitâ, the aggregation of hymns into Maṇḍalas, the reason for the positions assigned to the Maṇḍalas, and the method followed in placing each particular hymn. If my deductions prove accurate, it is evident that a fresh impetus will be given to the study of these remarkable documents, for the clue to the labyrinth will be in the hands of future investigators.