Where S. & N. make a contract about the conveyance of a farm by S. to N. who pays a certain sum in cash, and agrees to pay a further sum at a future time, and execute a mortgage for the balance of the purchase price, at which time S. agrees to make a deed to the farm, giving possession of the same; and at the same time it is further agreed that if N. fails to pay the further sum of money and to execute the mortgage, then the money paid shall be forfeited to S; Held, that such an instrument is a contract of sale, and not a sale itself. Stewart v. Fowler, 37 Kan. 677, 15 P. 918.