(M19) The bibliography of the subject is best dealt with under each general division; but reference must be made to works dealing with the subject as a whole. Professor J. Oppert’s _Documents Juridiques_ was the first successful attempt to deal with contracts in general and laid the foundation of all subsequent work. Dr. F. E. Peiser and Professor J. Kohler’s _Aus Babylonischen Rechtsleben_ deals with the later Babylonian documents as far as they throw light upon social life and custom. Professor Sayce’s _Babylonians and Assyrians_ makes large use of the data given by the contracts. Dr. T. G. Pinches’s _The Old Testament in the Light of the Monuments of Assyria and Babylonia_ also gives a very full account of what may be gleaned from them. The present writer’s _Assyrian Deeds and Documents_ makes an attempt to treat one branch fully. This work can only present the most essential facts. The whole amount of material is so vast, so much is yet unpublished, so many side-issues arise, all worth investigating, that it can only serve to introduce the reader to a fascinating and wide field of study. (M20) The material with which we have to deal, for the most part, falls very naturally into epochs. The early Babylonian documents, though very numerous, are mostly of the nature of memoranda and include few letters or contracts. The documents of the First Dynasty of Babylon are extremely rich in examples of both contracts and letters. Then the Tell Amarna letters form a distinct group. The Ninevite contracts and letters of the Sargonid Dynasty are well marked as separate from the foregoing. Lastly, those of the New Babylonian Empire are a group by themselves. A few scattered examples survive which form intermediate groups, usually too small to be very characteristic, and certainly insufficient to justify or support any theory of the intermediate stages of development. (M21) It must be observed that to a great extent these groups are not only separated by wide intervals of time—several centuries as a rule—but that they are locally distinct. The first comes from Telloh, the larger part of the second from Sippara, the third from Egypt (or Syria), the fourth from Assyria, the last from Babylonia. Whether the documents of Sippara in the third period showed as great divergence from those of the second period as the Tell Amarna letters do, or whether each group is fairly characteristic of its age in all localities using the cuneiform script, are questions which can only be answered when the other documents of that period are available for comparison.