1. The appellant sued to recover the sum of Rs. 3,750/- and interest from the first defendant, who may be referred to as the respondent, and from the estate of his deceased brother Poppattalal, represented in the suit by his widow and children, who are respondents 2 to 4. Poppattalal and the respondent sold a property to the appellant by Ext. P-2 in the year 1119, for a consideration of Rs. 3,750/-. At the time, there was in force, a contract for the sale of the property to Mohammed for Rs. 1,651/- of which they had received Rs. 1000/- in advance. Mohammed sued the respondents and others, including the appellant and Pw.1 the assignee of the property from the appellant under Ext. P-1, in O.S. 105 of 1121 for specific performance of the contract. On the impleadment of Pw.1 on the basis of Ext. P.1, the appellant was removed from the array of parties. In second appeal, specific performance was allowed and the case was remanded for passing a final decree on settlement of the value of improvements, if any, payable to Pw.1. Before the final decree was passed, the appellant commenced the suit from which this second appeal arises, on the 22nd January, 1957, for refund of the co