In Allore v. Jewell, 94 U.S. 506 (1876), which was a bill to cancel a conveyance of land alleged to have been obtained by the grantor a few weeks before her death, when from her condition she was incapable of understanding the nature or effect of the transaction, it was held that a lapse of six years before bringing suit to cancel the conveyance could not avail the defendant, where he had possession of the land and a reasonable rent therefor was equal to the value of his improvements, and there had been no loss of evidence preventing a full presentation of the case.