The respondents entered into a contract to purchase a property including mines and works for making certain types of metals. In the course of negotiations, the vendor-appellant made certain statements as to the earnings and capabilities of the property. With the consent of the vendor, the respondents appointed a team, which included experienced agents to ascertain the correctness of the seller's assertions. The team examined the property and works as well as the accounts kept by the vendor. The team received all the assistance required from the seller. The team then reported to the purchaser that the vendor's statements were substantially correct and the sale was then completed. Four months later, the purchasers discovered that the statements were untrue and they tried to rescind. Advise.