J. M. SHELAT, J. ( 1 ) AMONGST the several issues raised by the learned trial Judge were issues Nos. 1 and 2 viz. whether the plaintiff proved that the accident was the direct result of rashness or negligence on the part of the defendants drivers and whether the defendant-corporation proved that there was contributory negligence on the part of the plaintiffs. In para 9 of his judgment in suit No. 175/1953 the learned trial Judge held that the defendant corporation failed to adduce any evidence to establish contributory negligence on the part of the plaintiffs and found against the defendant on that issue. As regards the question whether the accident took place in consequence of rash or negligent driving on the part of the drivers the learned Judge observed that in cases of this type it would be enough if the plaintiffs were to establish the accident; that it was not necessary for such a plaintiff to lead positive evidence to prove negligence on the part of the defendants servants as from the mere fact of an accident the law would assume that the burden of proving negligence has been discharged by the plaintiff and the defendant would then have to meet a prima facie case established by the plaintiff. He further observed that a public carrier of passengers owed duty to the passengers to take every precaution for their safety and if a passenger were injured as a result of collision or accident it would be the duty of the carrier to prove that he took every possible precaution to ensure the safety of the passengers. ( 2 ) THE principles on which such suits are decided are well known. The general rule that it is for the plaintiff to prove negligence and not for the defendant to disprove it would in some cases cause considerable hardship to the plaintiff as the true cause of the accident might be solely within the knowledge of the defendant. The plaintiff may be able to prove the accident but it might well be that he cannot prove how it happened 80 as to show its origin in the negligence of the defendant. This hardship is avoided to a considerable extent by the rule Res lpsa loquitur. The plaintiff may be able to prove the accident but it might well be that he cannot prove how it happened 80 as to show its origin in the negligence of the defendant. This hardship is avoided to a considerable extent by the rule Res lpsa loquitur. There are cases in which the accident speaks for itself so that it is sufficient for the plaintiff in such cases to prove the accident and no more. It would be then for the defendant to show that the accident arose through no negligence of his. The maxim Res ipsa loquitur applies whenever it is so improbable that such an accident could have happened without the negligence of the defendant that a reasonable jury could find without further evidence that it was so caused. It is true that there must be reasonable evidence of negligence but where the thing is shown to be under the management of the defendant or his servants and the accident is such as in ordinary course of things does not happen if those who have the management use proper care it affords reasonable evidence in the absence of an explanation by the defendant that the accident arose from want of care. On the other hand if the defendant produces a reasonable explanation equally consistent with negligence and no negligence the burden of proving the affirmative that the defendant was negligent and that his negligence caused the accident would still remain with the plaintiff. ( 3 ) MR. Thakore for the defendant-corporation however argued that except for the bare word of the plaintiffs that the buses were being driven rashly or negligently by the drivers there was no positive evidence that a particular driver in whose vehicle the plaintiff was travelling was either rash or negligent while driving his vehicle. He contended that unless it was established by the plaintiffs that the driver of the vehicle in which he was sitting drove the vehicle either rashly or negligently it would not be possible to attribute the collision either to his rashness or negligence. He argued that it might be that it was the other driver who was responsible for the collision and not the driver of the vehicle in which the particular plaintiff was travelling. He argued that it might be that it was the other driver who was responsible for the collision and not the driver of the vehicle in which the particular plaintiff was travelling. Such a question no doubt would arise in a case where the two vehicles concerned in the collision were to be owned by different proprietors and are plied by the servants of such different proprietors. But where the drivers of both the vehicles concerned in the collision are servants of the same master that question would hardly arise. For even if one of the drivers is not proved to have driven his vehicle either rashly or negligently collision of two vehicles not being an ordinary event must be attributed to the rashness or negligence of one of the two drivers. Even if therefore it were found that it was the other driver who was responsible for rash or negligent driving which was the cause of the accident in question both the drivers being servants of the same master; the master would be liable for damages on the principle of vicarious liability. In Skinner. v. London Brighton and South Coast Railway Co. (1850) G Exch. 787 as reported in the Empire Digest Vol. VIII the plaintiff alleged that while he was a passenger in one of the defendants trains the train in which he was travelling ran against another train on the line whereby he was injured. The accident was caused by the train running in the direction against another train which was standing still at an intermediate station on the line. Both the trains were run and plied by the defendants and were being driven by their servants. It was held that the mere fact of the accident having occurred was prima facie evidence of the negligence on the part of the defendants. Although the driver of the defendants train which had halted at the intermediate station could not be attributed with any negligence or rashness there was negligence or rashness on the part of the other train which could be said to be the cause of the accident. The fact that the driver of the train which had halted was not negligent could not be relied upon as one relieving the defendants from their liability. The fact that the driver of the train which had halted was not negligent could not be relied upon as one relieving the defendants from their liability. Both the trains being owned by the defendants and being driven by their servants it would not matter whether one or the other driver was negligent and/or rash. The fact that both of them were the servants of the defendants coupled with the fact that the negligence on the part of one of them was responsible for the accident causing injury to the plaintiff was sufficient to hold the defendants liable for damages. ( 4 ) IN neither of the two suits the defendant corporation led any evidence. On the other hand the plaintiffs not only led their own evidence but also examined other witnesses including one of the passengers in the bus in which the plaintiff in suit No. 175 of 1953 was travelling. The evidence was cleat that the two plaintiffs were travelling in the two buses owned by the defendant corporation and while they were so travelling collision between the two buses took place in consequence of which both the plaintiffs suffered certain injuries. In the absence of any evidence led by the defendant corporation to show that there was no negligence on the part of their servants the learned Judge in our view was right in his findings on the two issues viz. (1) that the accident occurred as a result of negligence or rashness on the part of one or the other servant of the defendant corporation though such negligence or rashness cannot be necessarily attributed to one particular driver of the vehicle in which the plaintiff was when the accident took place and (23 that the defendant corporation failed to establish contributory negligence on the part of either of the two plaintiff. This being the position there can be no doubt on the evidence on record that the defendant-corporation was liable for the negligence and or rashness on the part of its servant or servants and was also liable to pay damages for the injuries sustained by the two plaintiffs. ( 5 ) [ His Lordship after discussing the evidence further observed: ] ( 6 ) THE learned trial Judge as we have said awarded Rs. 6000/as damages on the footing of 40% permanent incapacity caused by injuries to his right hand. ( 5 ) [ His Lordship after discussing the evidence further observed: ] ( 6 ) THE learned trial Judge as we have said awarded Rs. 6000/as damages on the footing of 40% permanent incapacity caused by injuries to his right hand. As we have said the plaintiff did not examine the doctor to testify the gravity of his injuries their nature and the incapacity permanent or otherwise if any or to show how long such incapacity would remain or last. The only evidence relied upon by the plaintiff is the certificate Ex. 59 on which the learned trial Judge found that as a result of the injuries sustained by the plaintiffs his right hand got permanent 50% incapacity. In our view the learned trial Judge was in error first in admitting and secondly in relying upon the certificate Ex. 59. It was contended by Mr. Vakil that the defendant had not raised any objection when this certificate was admitted in evidence by the learned Judge and that therefore the defendant corporation was precluded from raising any objection as to its admissibility at the stage of appeal. ( 7 ) IN our view the fact that defendant corporation had not raised any objection would not matter as the question relates to admitting an inadmissible piece of evidence on which objection can be taken even at the stage of appeal and not relating to the mode of proof of a document which is admissible. The distinction has been clearly brought out by the Privy Council in Gopal Das v. Sri Thakurji 46 Bom. L. R. 220 where it was held that where an objection to be taken is not that the document is in itself inadmissible but that the mode of proof put forward is irregular or insufficient it is essential that the objection should be taken at the trial before the document is marked as an exhibit and admitted to the record. A party cannot lie by until the case comes before a Court of Appeal and then complain for the first time of the mode of proof. The question therefore that falls for determination is whether the objection is as to the document being in itself inadmissible or as regards the mode of its proof. In our view a medical certificate such as Ex. The question therefore that falls for determination is whether the objection is as to the document being in itself inadmissible or as regards the mode of its proof. In our view a medical certificate such as Ex. 59 by itself is not a substantive or primary evidence particularly when it is relied upon to prove the opinion it contains. It is the opinion of the medical expert in such cases that is relevant. The certificate is only a record made by him which at best would show that he had recorded his view or opinion or made an entry as regards the injuries seen by him immediately after or at the time of his examination. At best such a certificate would have a corroborative value but it is not a substantive piece of evidence from which an opinion of the medical expert can be proved or established. Sec. 45 of the Evidence Act provides that when the Court has to form an opinion upon a point of science or art opinions on that point of persons specially skilled in such science or art etc. are relevant facts. What is thus made relevant under this section is the opinion of a medical expert or any other expert and not the document in which he has recorded his opinion. In our view therefore the certificate was not an admissible document. The objection now raised is as regards its inadmissibility and not as regards the mode of proof which if not objected to might perhaps amount to waiver of proof by a party to the suit. We are in this view fortified by a number of authorities. In Ali Akbar v. Java Bengal Line I. L. R. 1937 (2) Cal. 714 costelle A. C. J. and Edgley J. laid down that medical certificates were not themselves admissible in evidence. It was a case under the Workmens Compensation Act and the learned Judges observed that if the workman on his side and his employers on their side desired to place medical testimony before the Court they must do so by calling medical experts. Similarly in Coral Indira Gonslaves v. Joesph Prabhakar Iswariah A. I. R. 1953 Mad. 558 which was a case under the Divorce Act 1869 a certificate by a Doctor as regards the potency of the respondent was sought to be relied upon. Similarly in Coral Indira Gonslaves v. Joesph Prabhakar Iswariah A. I. R. 1953 Mad. 558 which was a case under the Divorce Act 1869 a certificate by a Doctor as regards the potency of the respondent was sought to be relied upon. Panchapakesa Ayyar J. held that such a certificate does not prove itself and it must therefore strictly be proved by the doctor who issues it. The doctor has to state what tests he had carried out to arrive at his conclusion and must stand cross-examination and convince the Court that his conclusion about the potency was correct. In Emperor v. Ahilya Manji I. L. R. 47 Bom. 74 also Marten and Crump JJ. held that a certificate from a Professor of Anatomy at the Great Medical College in Bombay as to certain bones submitted for his examination was not per se admissible in evidence but must be proved by calling the Professor as a witness. In Parwat Vedu Patil v. Sukhdev Shivram Patil A. I. R. 1956 Bom. 617 gajendragadkar J. held that the opinion sent by a handwriting expert cannot prove itself and unless the expert stepped into the witness box so as to enable the opponent to cross-examine him in reference to that opinion the opinion expressed by him in a communication to one of the parties cannot be treated as evidence under the Evidence Act. The same question arose in a Criminal Reference The State v. Karamsi Puna (1960) I G. L R. 155 before my brother Raju and relying upon the case of Emperor v. Ahilya Manji I. L. R 47 Bom. 74 he held that a medical certificate is no evidence unless the doctor who has issued it was examined and he gave his opinion in his evidence. It is clear from the opinions expressed in these decisions that the principle is that under section 45 of the Evidence Act it is the opinion of the expert that is made relevant and not the document in which it is expressed or communicated. Mr. Vakil however contended that an opinion can be expressed both orally as well as in writing. When an expert is called as a witness he expresses his opinion while in the witness box. Mr. Vakil however contended that an opinion can be expressed both orally as well as in writing. When an expert is called as a witness he expresses his opinion while in the witness box. If such expression of opinion is admissible by reason of section 45 of the Evidence Act there should be no reason why an expression of opinion in writing in a certificate cannot be relevant and admissible. There is however a misapprehension in the argument for it is the opinion and not the document in which such an opinion is recorded that is admissible. When a medical expert gives his evidence from the witness box he expresses his opinion through his evidence and it is that opinion which is made relevant under section 45 of the Evidence Act. The certificate therefore does not prove itself. The learned Judge therefore was in error in admitting the certificate and also in relying thereupon. ( 8 ) RAJU J. As important and substantial questions of law have been argued at great length I would like to add a few words regarding the questions of law. It is common ground between the parties that at about 4 p. m. on 9/09/1951 there was a collision between Bus No. B. Y. D. 2667 and Bus No. B. Y. D. 2645 both belonging to the Municipal Corporation of the city of Ahmedabad and that as a result of this collision injuries were caused to the plaintiff in suit No. 175/53 who was a passenger in Bus No. B. Y. D. 2667 and to plaintiff in suit No. 15/1953 who was a passenger in Bus No. B. Y. D. 2645. The main contention on behalf of the learned counsel for the Municipal Corporation is that in a case like this a plaintiff can succeed only by proving that the injuries to him were caused as a result of negligence on the part of the driver of the bus in which he was travelling. ( 9 ) IN a case like this where the plaintiff has filed a suit for damages the burden is on the plaintiff to prove that the injuries to him were caused as a result of negligence of the defendant or someone in the service of the defendant. ( 9 ) IN a case like this where the plaintiff has filed a suit for damages the burden is on the plaintiff to prove that the injuries to him were caused as a result of negligence of the defendant or someone in the service of the defendant. If in the ordinary course of things an accident would not have happened if the driver had taken due card and had not acted negligently the fact that the accident happened is prima facie proof that he had acted negligently. This is the principle of Res ipsa loquitur. From this principle it is possible to infer prima facie negligence on the part of a particular person. But in the case of an accident between two moving bodies in charge of different persons this principle will not fix the negligence of a particular person but the same principle can be applied in a slightly different manner. If in the ordinary course of things a collision would not have occurred between two moving bodies in charge of two different persons Q and Z if both had taken due care and had not acted negligently the fact that there was such collision would be prima facie proof that either Q or Z or both of them acted negligently. But in such cases this principle of Res ipsa loquitur would not be of any assistance in fixing the negligence of one of the two drivers. In the present case this prima facie proof of negligence of either of the two drivers has not been rebutted because neither the drivers nor any other person has been examined to show that the drivers had taken due care. It can therefore be held that the accident was due to the negligence of either of the drivers or both of them. In this case the drivers of both the vehicles happen to be servants of the defendant. The defendant would be liable because the accident was due to the negligence of one of the two drivers or of both the drivers and both are servants of the defendant. I therefore agree with my learned Brother that the defendant is liable to pay damages in both the suits. The defendant would be liable because the accident was due to the negligence of one of the two drivers or of both the drivers and both are servants of the defendant. I therefore agree with my learned Brother that the defendant is liable to pay damages in both the suits. ( 10 ) ANOTHER question of law that was canvassed related to the admissibility of the two medical certificates issued by two doctors regarding the injuries of the plaintiffs and the consequent incapacity of two plaintiffs. These two medical certificates have been admitted at the trial of the suit without objection but in appeal the learned counsel for the Corporation has strenuously contended that the medical certificates are not admissible in evidence as the doctors who issued them have not been examined as witnesses and that it is open to him to take this objection in appeal. It is however first contended by the learned counsel for the respondents that the medical certificates are admissible in evidence. According to him the opinion of a Medical officer may be either written or oral and is admissible in either form. ( 11 ) IN the instant case medical certificates have been admitted in evidence without objection although the doctors who issued them were not examined as witnesses. It is therefore contended that the certificates are inadmissible in evidence to prove the nature of the injuries and the nature of the resultant incapacity of the plaintiff. Sec. 165 of the Evidence Act provides that the judgment must be based upon facts declared by the Evidence Act to be relevant and duly proved. Sec. 5 of the Evidence Act provides that evidence may be given in any suit or proceeding of the existence or non-existence of every fact in issue and of such other facts as are hereinafter declared to be relevant and of no others. The nature of injuries sustained by the plaintiff and the nature of his incapacity are of course relevant facts on the question of damages. These relevant facts are sought to be proved by the opinion of the doctor contained in the medical certificate. The opinion of a doctor as to the nature of injuries and the nature of the incapacity is relevant under sec. 45 of the Evidence Act. Such opinion however must be duly proved. These relevant facts are sought to be proved by the opinion of the doctor contained in the medical certificate. The opinion of a doctor as to the nature of injuries and the nature of the incapacity is relevant under sec. 45 of the Evidence Act. Such opinion however must be duly proved. Sec. 59 provides that all facts except the contents of documents may be proved by oral evidence. The relevant fact is the opinion of the doctor and not the contents of a document. The opinion of the doctor must as provided in sec. 60 of the Evidence Act be proved by the evidence of the person who holds that opinion. Sec. 60 lays down the only manner of proving such opinion. We are not dealing with opinions of experts expressed in treatises which are dealt with in the proviso to sec. 60. Sec. 60 is imperative and provides that the only manner of proving the opinion of a doctor is by the evidence of the person who holds that opinion. The medical certificates should not therefore have been admitted in evidence as evidence of the opinion of the doctor. ( 12 ) THE learned counsel for the respondents however contends that even if the medical certificate was inadmissible in evidence to prove the opinion of the doctor that objection not having been taken in the first Court cannot be taken in appeal. He contends that the objection is one regarding the mode of proof of the medical certificate and should not be allowed to be urged in appeal as no objection had been taken at the hearing of the suit. Relying on Gopal Das v. Sri Thakurji 46 Bombay Law Reporter 220 a decision of the Privy Council he contends that objection regarding the mode of proof of evidence cannot be taken for the first time in appeal. It is contended that Part II of the Evidence Act relates to the proof of relevant facts and that if the objection taken in appeal is that a certain fact has not been proved in the manner laid down in Part II of the Evidence Act such an objection cannot be taken for the first time in appeal as laid down by their Lordships of the Privy Council. ( 13 ) IT is therefore necessary to decide whether this contention is correct. ( 13 ) IT is therefore necessary to decide whether this contention is correct. In the above cited case their Lordships of the Privy Council observed as follows:where the objection to be taken is not that the document is in itself inadmissible but that the mode of proof put forward is irregular or insufficient it is essential that the objection should be taken at the trial before the document is marked as an exhibit and admitted to the record. A party cannot lie by until the case comes before a Court of Appeal and then complain for the first time of the made of proof. ( 14 ) THEIR Lordships no doubt used the expression `mode of proof and observed that where the objection is that the mode of proof is irregular or insufficient it is essential that the objection should be taken at the trial. Their Lordships were however referring to the mode of proof of documents and not to the whole Chapter on mode of proof in the Evidence Act. It is settled law that objection to hearsay evidence can be taken even in appeal although section 60 of the Evidence Act which prohibits hearsay evidence is in Part II of the Evidence Act dealing with proof of relevant facts. ( 15 ) SEC. 5 of the Evidence Act provides that evidence may be given of facts in issue and relevant facts and of no others. Then follow provisions explaining when facts are relevant. The manner of proving relevant facts (which expression will here be taken to include facts in issue) is then explained in Part II of the Evidence Act. In regard to certain types of relevant facts the Evidence Act provides more than one method of proving relevant facts and explains in what circumstances and under what condition the second method of proof may be used. When a relevant fact is proved by a method of proof permissible under certain circumstances if no objection is taken in the first Court as to the method of proof then no objection can be taken in appeal that the method of proof is contrary to the provisions of the Evidence Act. When a relevant fact is proved by a method of proof permissible under certain circumstances if no objection is taken in the first Court as to the method of proof then no objection can be taken in appeal that the method of proof is contrary to the provisions of the Evidence Act. The reason for this rule is that when a method of proof is permissible under certain circumstances the failure to take objection is tantamount to an admission that the circumstances exist which would make the method of proof adopted proper. It is only in this typo of cases that the principle laid down by the Privy Council in 46 Bombay Law Reporter 220 applies. That principle does not apply to cases where the Evidence Act permits only one method of proof. In such cases that method of proof and no other can be adopted to prove relevant facts. ( 16 ) FOR instance all facts except the contents of documents must be proved by oral evidence which must be direct (see sections 59 and 60 ). Objection can be taken for the first time in appeal if facts are proved by oral evidence which is not direct that is which is hearsay. Such an objection can be taken for the first time in appeal although such objection relates to the mode of proof of relevant facts. ( 17 ) IN the case of contents of documents two methods of proof are recognised by the Evidence Act as sec. 61 provides that the contents of documents may be proved either by primary or by secondary evidence. There are some sections in the Evidence Act which explain in what circumstances and under what conditions the second method of proof can be availed of. For instance see secs. 65 to 73. When a method of proof has been adopted which is permissible in certain circumstances and under certain conditions the failure to take objection when evidence is first tendered amounts to an admission that the circumstances contemplated exist and that the conditions necessary are complied with. It is to such cases that the principle of 46 Bombay Law Reporter 220 applies. In such cases no objection can be taken for the first time in appeal. It is to such cases that the principle of 46 Bombay Law Reporter 220 applies. In such cases no objection can be taken for the first time in appeal. When the Evidence Act provides that a relevant fact shall be proved only in one manner objection can be taken in appeal if a different method had been adopted whether with or without consent to prove a relevant fact. But if the Evidence Act provides two methods of proving a relevant fact and further provides that the second method may be used in certain circumstances and under certain conditions if the second method had been adopted without objection no objection can be taken up in appeal that the requisite conditions and circumstances did not exist because the failure to take objection in the first Court will be tantamount to an admission that the requisite circumstances existed and that requisite conditions had been fulfilled. It is in such cases that no objection can be taken in appeal to the proof of documents. Such cases are cases where the document is itself relevant and the contents of a document are sought to be proved. The principle laid down by the Privy Council is restricted to such cases. That principle does not apply where as in this case the opinion of an expert is sought to be proved by the certificate issued by him and not by his evidence which is contrary to sec 60 of the Evidence Act which lays down the only method of proof of opinion of an expert. Sections 65 to 72 relate to the mode of proof of the contents of documents and in such cases as the Privy Council has laid down if no objection has been taken in the first Court objection cannot be taken in the first appellate court or in second appeal. But if the infirmity in the evidence relates to its relevancy or to the manner in which evidence is given then objection can be taken for the first time even in appeal. Sec. 165 provides that the judgment must be based upon the facts declared by the Act to be relevant and duly proved. But if the infirmity in the evidence relates to its relevancy or to the manner in which evidence is given then objection can be taken for the first time even in appeal. Sec. 165 provides that the judgment must be based upon the facts declared by the Act to be relevant and duly proved. I am therefore of the view that there is no merit in the contention that in view of the Privy Council decision in 46 Bombay Law Reporter 220 no objection can be taken for the first time in appeal when the objection is based on a non-compliance with the provisions of the Evidence Act in Part II relating to proof. ( 18 ) THE Evidence Act does not make a medical certificate relevant except in some special cases such as those referred to in section 32. Excluding such special cases it is the opinion of the doctor that has to be proved as a relevant fact and not the medical certificate. The doctor who issues a medical certificate stating his opinion has to be examined to give evidence in the only permissible way of his opinion and not as observed in Coral Indira Gonslaves v. Joseph Prabhakar A. I. R. 1953 Madras 558 to prove the certificate. Even though the signature on the medical certificate is proved the certificate would not be evidence of the opinion of the doctor except in such special cases as those referred to in section 32. ( 19 ) IN certain special cases the medical certificate may itself be relevant as when section 32 of the Evidence Act applies. But this is not one of such cases. ( 20 ) A medical certificate can however be proved to corroborate the substantive evidence of the doctor after he has been examined as a witness as provided in section 157 of the Evidence Act. In such cases the substantive evidence is the oral evidence of the doctor and not the certificate. . ( 21 ) I therefore agree with any learned Brother that the medical certificate in the instant case has been wrongly admitted in evidence. ( 22 ) AS regards the quantum of damages I fully agree with my learned Brother. I therefore agree with the conclusions of my learned Brother and concur in the order proposed by him. ( 23 ) APPEAL allowed: Amount of compensation reduced .