In some cases even an entire contract is apportionable, as where the price to be paid is not fixed, or is by the contract itself apportioned according to time; so, if the failure of one party to perform is caused by the act of the 20 13-1-10 other, the contract may still be apportioned. (Orig. Code 1863, § 2688; Code 1868, § 2684; Code 1873, § 2726; Code 1882, § 2726; Civil Code 1895, § 3644; Civil Code 1910, § 4229; Code 1933, § 20-113.)