A more thorough explanation:

Master in Lunacy

A Master in Lunacy is a historical judicial officer who was appointed by the Lord Chancellor to investigate the mental state of individuals who were believed to be incapable of managing their own affairs due to mental illness. The Master in Lunacy was responsible for ensuring that the individual's property was managed properly for their benefit.

For example, if a person was believed to be suffering from a mental illness that made it difficult for them to make decisions about their finances or property, a Master in Lunacy would be appointed to investigate their mental state. The Master in Lunacy would then make a determination about the individual's mental capacity and would oversee the management of their property to ensure that it was being used for their benefit.

Another example would be if a person was suffering from a mental illness that made it difficult for them to care for themselves. In this case, a Master in Lunacy would be appointed to investigate their mental state and would oversee their care to ensure that they were receiving appropriate treatment and support.

These examples illustrate how the role of the Master in Lunacy was to protect the interests of individuals who were unable to manage their own affairs due to mental illness.