Professor Keener's treatise on Quasi Contracts appeared in 1893. It has done much to clarify the views of lawyers and teachers, and undoubtedly has had a salutary influence in the development of the law. For some time, however, there has been urgent need of a book containing a further analysis and classification of quasi contractual obligations, a more thorough treatment of many parts of the subject, and a larger collection of modern authorities. It was with the hope of meeting this need that the present work was undertaken.

I wish to acknowledge my indebtedness to previous writers. The treatise of Professor Keener and the case books of Professor Scott and Professor Woodruff have been invaluable, and various contributions to the literature of the subject by Professor Ames and Professor Williston of Harvard, Professor Wigmore and Professor Costigan of Northwestern, and Professor Corbin of Yale, have been of the greatest assistance. I desire also to record my appreciation of helpful criticism and advice received from Professor Wigmore and my colleague Professor Cathcart, and of intelligent assistance from Walter Slack, Esq., of the San Francisco Bar.

The greater part of Chapter III (General Principles (Continued) Misreliance Resulting From Mistake Of Law) has already appeared in the form of an article in the Columbia Law Review, and is reproduced here, with some modification, by the courtesy of the publishers of the Review.

F. C. W.

Stanford University, California, October 26, 1912.