"The requirement of the law that a sale must have for its object a determinate thing, is fulfilled as long as, at the time the contract is entered into, the object of the sale is capable of being made determinate without the necessity of a new or further agreement between the parties (Art. 1273, old Civil Code; Art. 1460, New Civil Code). The specific mention of some of the lots plus the statement that the lots object of the sale are the ones needed for city hall site, avenues and parks, according to the Arellano plan, sufficiently provides a basis, as of the time of the execution of the contract, for rendering determinate said lots without the need of a new and further agreement of the parties."