JUDGMENT : This as defendants revision against an order passed by the Civil judge, First Class, Indore in Original Suit No. 391/55 A on the 25th January, 1956. The facts are that the plaintiff, who is the opponent in this revision, filed a suit for the sale of property against the petitioner-defendant on the basis of a mortgage deed. The defendant admitted the execution of the document but resisted the suit on the ground that the mortgaged property dees not belong to the defendant alone, but is the joint family property; that the rate of interest is illegal; that the defendant has paid Rs. 1414-6-0 in this account which the plaintiff has not adjusted. On the basis of these pleadings, three issues were framed. The burden of proof in all these issues was on the defendant. The defendant wanted to prove Ex. D/1, a receipt alleged to have been signed by the plaintiff and his Vakil Shri Kotwal. The defendant, therefore, summoned Mr. Kotwal as his own witness. It seems Mr. Kotwal did not turn up, but asked his client to go to the witness-box and admit the receipt Ex. D-1. It may be noted here that the defendant had hot asked the plaintiff to come as his witness. He had definitely asked for Mr. Kotwal to come as defendants witness and if it was a mistake, it was the mistake of the counsel to send the plaintiff to the witness-box, for, the receipt (Ex. D/1) could have been admitted by the plaintiff without going to the witness-box at all. The plaintiff, however himself went to the witness-box, took the oath and then was examined by Mr. Kotwal and admitted his signatures on the receipt (Ex. D/1). The defendant at that stage wanted to cross-examine the plaintiff about the whole suit but the Court made it clear that only those questions will be allowed which pertain to the document Ex. D/1. Against this order the defendant has come in revision to this Court. 2. The law on the point is laid down in S. 138 of the Indian Evidence Act, the material portion of which runs as follows:- "Witnesses shall be first examined-in-chief, then, (if the adverse party so desires) cross-examined, then (if the party calling him so desires) re-examined. D/1. Against this order the defendant has come in revision to this Court. 2. The law on the point is laid down in S. 138 of the Indian Evidence Act, the material portion of which runs as follows:- "Witnesses shall be first examined-in-chief, then, (if the adverse party so desires) cross-examined, then (if the party calling him so desires) re-examined. "The examination and cross-examination must relate to relevant facts but the cross-examination need not be confined to the facts to which the witness testified on his examination-in-chief". On the basis of this provision of law, Mr. Dubey contends that his right of cross-examining the plaintiff cannot be fettered by the Court and by putting a limit the Court below has acted in excess of jurisdiction vested in him. I think this contention is well-founded. Cross-examination cannot be confined to matters proved in examination-in-chief. As Phipson observes (see Phipson on Evidence 9th edition, page 497), "the slightest direct examination, even for formal proof, opens up the whole of the cross-examiners case. With the above view, the witness can be asked not only as to facts in issue or directly relevant thereto, but all questions which, though otherwise irrelevant, tend to impeach his credit in the manner provided". 3. In the present case, there is no doubt the plaintiff ought not to have stepped into the witness-box, for he could have admitted the document without taking the oath; but due to some mistake on the part of his counsel he took oath and, then, made a statement admitting his signatures on the document. No doubt he was sworn by mistake and also examined by mistake. But when once he is examined-in-chief by mistake, can it be contended that he cannot be cross-examined as to the whole suit? 4. Regarding witnesses sworn by mistake, the rule is thus laid down in Art. 1893 of Volume 6 of "Wigmore on Evidence" (1940-3rd edition-at page 563) :- 1. A person who has been sworn by mistake, as sometimes happens under the practice of swearing in a group, and has not yet been put on the stand, is not yet the witness of the party for whom he has sworn. 2. A person who has been sworn by mistake, as sometimes happens under the practice of swearing in a group, and has not yet been put on the stand, is not yet the witness of the party for whom he has sworn. 2. A person sworn but not yet asked any question is not the witness of the party swearing him; moreover, he cannot be cross-examined even to discredit him, for there is as yet no testimonial assertion to be discredited. 3. A person sworn and asked questions, Where he gives no answer or where the facts in his answer are irrelevant to the case, has not yet become his partys witness. 4. A person who is questioned and answers merely to prove a document does become a witness of the party thus using him". At page 565, the third sub-section of para 1894 runs as follows:- "A person producing a document and answering questions tending to prove it does become the questioners witness". Applying the principle of sub-para 4 of para 1893 read with the third sub-para of para 1894 it should follow that once the plaintiff even by mistake comes to the witness-box and swears and is examined about a document, he would become a witness and will be liable to be cross-examined by the defendant. Under S. 138 of the Evidence Act, cross-examination cannot be confined to the facts to wlhich the witness testified in his examination-in-chief. He can be cross-examined as to the whole of the case. 5. In this view of the matter, the order passed by the Civil Judge, First Class, Indore, on 25th January,1956, Was not correct. The defendant had a right of cross-examining the plaintiff on the whole suit and clearly the Courts act in debarring the defendant of his right to cross-examine so, would amount to an illegal assumption of jurisdiction not vested in it. It is, in my opinion, also an error of procedure in the course of the trial which is material as it is bound to affect the ultimate decision of the case and would amount to an illegality or material irregularity in the exercise of jurisdiction within the meaning of S. 115 (c) C. P. C. This revision is therefore, allowed with costs and the order dated 25th January, 1956 is set aside. The Court is directed to proceed according to law in the light of the observations made above.