Mrs Potts was the widow of ,I think Thomas Potts who died in around 1800. It seems he had been a successful business man in Edinburgh and left a generous estate. When his wisow died some years later, all hi male relatives had predeceased him asn she did not wish the money to go directly to the spouses of his surviving siblings so she left it in trust to their descendants in equal portions - three families in which each generation inherited the income shared equally. After one and a half centuries, the beneficiaries had multiplied to the extent that the cost of administration was greater than the disbursement of benefit. It took around 20 years to wind up the trust and distribute the remaining capital, which was completed in about 1950. The interest is that the names of the families are in the document which can assist in identifying the correct spouses!