The nineteenth century witnessed a continuous growth in both the number of lunatic asylums, and in the numbers of people held within them. For many, contemporaries, and more recent commentators alike, the period was marked by the growing failure of the asylum as a curative institution. The reasons cited for this failure have varied, and at different times attention has focussed on a number of key themes. The purpose of this thesis is to critically examine each of these themes and to assess the expectations of those who built the asylum, those who worked in it, those who lived near it, and perhaps most importantly of all, those who used it. As such, the six chapters examine the asylum management and their motivations; the social separation of the insane patient, and how this was affected by external factors; the asylum's relationship with the various Poor Law authorities; the motivations that the families of the insane had for committing, and not committing their kin; the treatment regimes within the asylums, and how they differed between the sexes; and the central role that the asylum attendants had in caring for the insane. In each of these areas, perceptions of the asylums' supposed failure will be called into question, and there will be a continuing consideration of its function as both a custodial and a curative institution. Recent studies of extra-institutional care have emphasised that treatment in the asylum remained just one option in the `mixed economy of care'. Building on this, this thesis contests that the continued growth and development of the asylum system could not rest on its custodial function alone. Conversely, it shows that its ability to `cure' significant numbers of people continued to be a significant factor throughout the period.