The very idea of a "fusion fallacy" and the central importance of the effect of the Judicature legislation upon common law and equity is associated with New South Wales. Yet the Supreme Court of New South Wales was constituted in 1824 as a single court with broad jurisdiction at common law and in equity. One hundred and fifty years later, legislation was required to fuse its separate common law and equity "sides". How did that fission come about? This chapter, largely based on unpublished primary records, seeks to explain how that occurred.