William F. Johnson sued the Bissell Motor Company, alleging the breach of a contract by which defendant agreed to sell for plaintiff an automobile at the price of $600. Plaintiff introduced in evidence a paper writing which witnessed an order by defendant’s sales agent on defendant for the immediate delivery of an automobile at the price of $600. One expression of the order was that defendant “will not be bound by. any agreement -or promise not herein stated.” The price was paid and defendant delivered the automobile. The order was signed by R. K. Kay, sales agent for defendant, and across its face was written, “I agree to sell car within 90 days if decide to sell car,” and this constituted the contract alleged to have been breached.

It was competent probably to'explain by parol that the contract was entered into by Kay as agent for defendant and that defendant, by accepting the order, undertook to resell the automobile according to the terms o,f the contract written across its face. 2 Williston on Contracts, p. 1230; Hughes v. Wilkinson, 35 Ala. 462. But the court, over defendant’s objection allowed plaintiff to show that the agreement was that defendant was to resell the automobile for plaintiff at the price of $600, thus very materially affecting the amount of recoverable damages in the event the jury found with plaintiff, and it seems very clear that the jury by its verdict fastened upon defendant, not only the contract as it was written, but the alleged stipulation as to the price as well. In this the court went counter to the authorities which hold that, while a contract may be explained consistently with its terms, oral evidence of a term not shown by the writing is not admissible ' in actions ex contractu, where no fraud is charged, because its effect is to vary .the terms of the written instrument by superadding another term or condition not expressed by the parties. Bush v. Bradford, 15 Ala. 317; Tabor v. Peters, 74 Ala. 90, 49 Am. Rep. 804; Griel v. Lomax, 86 Ala. 137, 5 South. 325. The practical effect of the much discussed parol evidence rule is that, when the court sees that a separate collateral agreement was probably intended by the parties, evidence of it is admitted. 2 Williston on Contracts, §§ 631-638. Prof. Williston quotes the following from Fuller, C. J., in Seitz v. Brewers’ Refrigerator Co., 141 U. S. 510, 12 Sup. Ct. 46, 35 L. Ed. 837, as being a good expression of the principle:

“Undoubtedly the existence of a separate oral agreement as to any matter on which a written contract is silent, and which is not inconsistent with its terms, may be proven by parol, if under the circumstances of the particular' case it may be properly inferred that the parties did not intend the written paper to be a complete .and final statement of the whole of the transaction between them. But such an agreement must not only be collateral, but must relate to a subject distinct from that to which the written contract applies; that is, it must not be so closely connected with the principal transaction as to form part and parcel of it. And when the writing itself upon its face is couched in such terms as impart a complete legal obligation without any uncertainty as to the object or *40 extent of the engagement, it is conclusively presumed that the whole engagement of the parties, and the extent and manner of their undertaking, were reduced to writing.”

The - burden is on the proposer to show the propriety of the suggested exception. An indiscriminate recognition of exceptions would practically annul the rule itself, would deprive written contracts of their certainty, and render prudent men powerless to protect themselves. Graham v. Savage, 110 Minn. 513, 126 N. W. 394, 136 Am. St. Rep. 527, 19 Ann. Cas. 1022. Two considerations induce the conclusion that plaintiff should not have been allowed to superadd tlie term indicating, as he contended, the price at which defendant agreed to sell the automobile for him. The superadded term, if in fact, agreed upfcra, was of the very substance of the contract and should have been included within its written expression; the writing on its face — we refer here to the language of the order, quoted above, as prop.er to be considered in the construction of the promise written across the face of the paper —-purported to evidence the complete legal obligation undertaken by defendant. For these reasons our opinion is that the court erred in admitting the testimony in question.

Some charges refused to defendant— among them the general affirmative charge— are discussed in the brief, but these cannot be reviewed in the absence of a recital in the bill of exceptions that it contains’all the evidence. Wadsworth v. Williams, 101 Ala. 264, 13 South. 755; Anniston Mfg. Co. v. So. Ry., 145 Ala. 351, 40 South. 965.

We find no other error.

Reversed and remanded.