after making the foregoing statement, delivered the following opinion of the court.

In the view we take of the case it will be necessary for us to consider only one of the questions presented by the assignments of error, and that is this:

1. Was the verdict of the jury plainly without any evidence of probative value to support it, in its finding that the blindness of the plaintiff was caused by the original injury to his tooth or by the subsequent dental treatment thereof?

The question must be answered in the affirmative.

The uncontroverted testimony in the case is to the effect that the blindness of the plaintiff was due either to primary or secondary atrophy of the optic nerve; that primary atrophy is caused by trouble in the nervous system of the spinal cord usually; that secondary atrophy is caused by inflammation of the optic nerve, which in turn has four classes of causes — first, ocular or disease in the interior eye; second, orbital, in which there is a direct injury to the orbit, or bony cavity of the skull which contains the eye, sufficient to break the canal through which the optic nerve runs from the cranium to the eye, which would produce an inflammation which would likely be followed by atrophy; third, diseases of *221the brain, such as tumors, epidemic diseases, rheumatism “and so forth ad infinitum,” diabetes, Bright’s disease “and things of that sort,” pneumonia, therumatism, lead poisoning, alcohol poisoning, wood alcohol poisoning and all the different infections or rather intoxications. A witness on this subject, Dr. Myers, in his testimony, which is not controverted by any other witness in the case, stated that “any of those things could produce an optic atrophy and I have only given just about half of them.” The testimony is also uncontroverted to the effect that the nerves from the broken tooth of the plaintiff have no direct connection with the optic nerve. That the optic nerve runs from the eye back into the skull and that to break the canal through which that nerve runs there would have to be a thrust of some instrument into the eye socket, or a blow on the head or elsewhere hard enough to break the canal. And that a man may have optic atrophy for “quite a long while” before it affects his vision. “He may be able to see quite well and still have optic atrophy perfectly proved.”

The uncontroverted testimony is also to the effect that while it was possible that the force exerted by the dentist in removing the tooth of the plaintiff may have been sufficient to have broken the canal of the optic nerve and have thus caused the optic atrophy, that that was “extremely improbable.” Indeed, if the dentist had been that violent in his treatment, it could scarcely be considered other than malpractice, for the result of which the defendant could not be held liable.

But, if it were granted (which is not) that the dental treatment had been shown by the evidence to have been a probable cause of the optic atrophy and it could be held that the defendant is liable for such aresult; still, that alone would not have established it as thé more probable cause of the injury complained of by the plaintiff.

*222The evidence for the plaintiff negatives the existence of only one of the other numerous possible causes aforesaid with any degree of positiveness. And when the utmost force and effect is given to the testimony of the plaintiff to the effect that he was not conscious of the presence of any disease, or of the existence of any other cause for the blindness, except the breaking and the extraction of the tooth;- and also to the statement of Dr. Myers, who merely examined the eyes of the plaintiff, to the effect that he (Dr. Myers) could not find any cause for the optic atrophy, there remain many other causes, all except one of which, according to the evidence, is equally probable as having been the cause of the atrophy in question as the accident to the tooth of which the plaintiff complains.

We do not have to determine whether this case falls within the principle of the authorities which hold, that, where the ascertainment of the cause of an injurious result to some part of the human body involves subjects about which a layman can have no knowledge at all, the court and jury are so dependent on expert evidence that there can be no other guide, and that in the absence of affirmative expert evidence to support a verdict in such a case, the verdict must be held to be without evidence to support it. See Ewing v. Goode (C. C.), 78 Fed. 442; Robbins v. Nathan, 189 App. Div. 827, 179 N. Y. Supp. 281; Hunter v. Burroughs, 123 Va. 113, 96 S. E. 360.

In the instant case, it is true, there was no affirmative expert evidence to support the verdict; but the plaintiff’s position was even worse. The only expert witness on the subject introduced by the plaintiff was Dr. Warden, who testified, in effect, that he attributed the symptoms, which he observed in his treatment of the plaintiff, to the anesthetic, which had been administered to him by the dentist (Dr. Willis), who first treated the *223plaintiff, or to neuralgic pain arising from the extraction of the tooth. The other uncontroverted expert evidence in the case shows affirmatively, as above set out, that the proof for.the plaintiff leaves it more than probable that there was some cause for the injury complained of other than the one for the result of which the defendant is liable. In such a condition of the proof it .is plain that the verdict in favor of the plaintiff was without evidence to support it.

The plaintiff relies upon certain facts which are shown by the evidence, namely, the facts that plaintiff’s vision was not affected until he received the dental treatment following the injury to his tooth; that he was, until that time, robust, feeling well, and in possession of all of his faculties, including sight; that coincidentally with the extraction of the tooth he experienced violent pain in the head, face and throat, and his sight became dim; that when, by means of a local application, the pain was relieved, the dimness of sight was removed, and upon a return of the pain the sight became again dim; and that this connection between the pain and the dimness of sight continued for some fifteen days, while the plaintiff was being treated by Dr. Warden. Merely from this data the conclusion is reached that the dental treatment was the cause of the .blindness. There are several obvious defects in this reasoning. First: The assumption is unwarranted that because the vision was not until then affected, the atrophy, which was the cause of the blindness, had no existence until then. This assumption is in direct conflict with the uncontroverted testimony of Dr. Myers, referred to and in part quoted above, in which he says that a man may have atrophy “quite a while” before it affects his vision. Secondly: It is matter of common knowledge, of which therefore the court will take judicial notice, that one *224may be robust and feel well, and yet be afflicted with some serious, even mortal disease. And there was no evidence in the instant case of any probative value on the subject of what was in fact the physical condition of the plaintiff immediately before the dental operation in question, so as to tend to show that he was not prior thereto affected with the atrophy, due to some of its many known causes. Plaintiff contented himself with introducing one witness (Dr. Sylvester), proving merely that the plaintiff was free from one form of disease which might have caused the atrophy. Thirdly: The remainder of the reasoning holds good as far as it goes, but it does not go far enough to sustain the conclusion as a sound deduction. It makes no mention of the data with respect to the absence of any concurrence of the restoration of sight with the relief of the pain after the first fifteen days during which that coincidence was observed.

It is true, of course, that the repeated concurrence of a supposed cause and effect tends to show that that relationship exists; and the greater the number of such instances of concurrence which are observed, the stronger becomes the presumption of the correctness of the assumption of the supposed relationship. But it is also true that the failure of the supposed cause to produce the effect in question, on a single occasion, accompanied by the same phenomena, will absolutely destroy the presumption being previously entertained, however well supported it may have seemed to have been by any number of concurrent events; for it thereupon becomes apparent that they were but coincidences, and that the effect which has been observed must have been due to some other cause.

And, unfortunately for the validity of the aforesaid reasoning in the instant case, although the dimness of *225sight was removed by each treatment during the aforesaid fifteen days, this did not occur thereafter when the pain had been then entirely relieved — which destroys all reliance to be placed on the correctness of the aforesaid conclusion, and tends to show that the blindness was due to some other cause, and one antecedent to, rather than to the pain or the eause of the pain.

A learned writer on the subject of deductive reasoning and of the fallacy of conclusions deduced from a part, instead of the whole, of the data available (McCaulay’s Essay on Lord Bacon, vol. 2, pp. 239, 240, of McCaulay’s Essays and Poems), has illustrated the subject as follows: “We have heard that an eminent judge of the last generation was in the habit of jocosely propounding after dinner a theory, that the eause of the prevalence of Jacobinism was the practice of bearing three names. He quoted on one side Charles James Fox, Richard Brinsley Sheridan; John Horne Took, John Philpot Curran, Samuel Taylor Coleridge, Theobald Wolf Tone. These were instantiae convenientes” (quoting from Lord Bacon’s Novum Organum). “He then proceeded to cite instances absentiae in proximo” (again quoting from that great work), “William Pitt, John Scott, William Wyndham, Samuel Horsley, Henry Dundas, Edmund Burke. * * * In this way our inductive philosopher arrives at what Bacon calls the vintage, and pronounces that the having of three names is the cause of Jacobinism. * * * If the learned author of the theory about Jacobinism had enlarged either of his tables a little, his system would have been destroyed. The names of Tom Paine and William Wyndham Grenville would have been sufficient to do the. work.”

As said in C. & O. Ry. Co. v. Catlett, 122 Va. 232, 94 S. E. 934: “* * * the preponderance of the evi*226de'nce rule does not dispense with the requirement that there must be some evidence which has some logical probative value to establish a fact, before that fact can be even considered as a possible hypothesis predicated upon the evidence. * * * a fortiori, before it can be considered as the more probable hypothesis from the evidence. In other words, the preponderance of the evidence rule can operate only upon hypotheses to establish which there is some evidence in the case of some logical probative value.” -

The following authorities are cited and relied on in argument for the plaintiff upon the subject under consideration, namely: Brumbaugh, Legal Reasoning and Briefing, p. 527; Shea v. Glendale, etc., Co., 162 Mass. 463, 38 N. E. 1123; Taylor v. General Accident Assurance Corporation, 208 Pa. 439, 57 Atl. 830; and Manufacturers’ Accident Indemnity Co. v. Dorgan (U. S. Cir. Ct. of App. 6th Cir.), 58 Fed. 945, 7 C. C. A. 581, 22 L. R. A. 620.

In Brumbaugh, Legal Reasoning and Briefing, page 527, what is said, which is quoted and relied on for the plaintiff, is as follows: “One of the most natural, simple and effective methods of organizing evidence for argumentative purposes is that afforded by the relation of cause and effect. It yields a tremendous leverage in forcing the mind to a conclusion, for the mind, however untrained and elementary in its mode of thought, can not escape the logical cogency of a canvas of facts which furnish an adequate cause, disclose an opportunity, and finally reveal subsequent results which find no solution or explanation, except upon the basis of the validity of the preceding circumstances.” (Italics supplied.) This statement is correct and is an admirable illustration of the accuracy and convincing force of the method of deductive reasoning. But, as appears from what is said above, *227the proof for the plaintiff does not bring the instant ease within the influence of such statement.

In Shea v. Glendale, etc., Co., it was decided that proof of the fact that persons, working under conditions like those under which the plaintiff worked, were affected in a manner like that in which the plaintiff was affected, was admissible in evidence as tending to support the inference that they were all injured by the same cause, namely, the poisonous condition of the atmosphere in the room where they worked. Moreover, in that case a physician testified that the illness of the plaintiff was probably a consequence of the poisonous condition of the atmosphere.

In Taylor v. General Accident Assurance Corporation the plaintiff’s intestate died as the result of being injured by a fall. There.was an autopsy and affirmative medical expert testimony to the effect that the fall caused the death. The only question at issue was whether the fall was accidental or not accidental; and the court held that as the autopsy disclosed that the fall was not caused by any diseased condition, within the meaning of the insurance policy, the accidental character of it might properly be inferred from the circumstantial evidence.

In Manufacturers' Accident Indemnity Co. v. Dorgan, also, there was a fall, and an autopsy which disclosed that the fall of the deceased was not caused by any diseased condition, within the meaning of the insurance policy. That being so, the court held that the jury could properly infer the accidental character of the fall from the circumstantial evidence.

A distinguishing feature of both of the two cases last cited, which is wholly absent from the case in judgment, is that, in those cases, there was affirmative evidence, derived from the physical examination at the autopsy of the body of the person injured, to the effect, that the *228injury complained of was not caused by any diseased condition of the person existing prior to the injury.

It is urged in behalf of the plaintiff that the defendant is estopped by asking for instruction No. 1 from taking the position that there is not sufficient evidence to sustain the verdict of the jury in finding that the blindness was caused by external, violent and accidental means, since the question whether such was the cause of the blindness was submitted to the jury at the request of the defendant by that instruction; and authorities are cited in behalf of the plaintiff to sustain that contention, including Kimball & Fink v. Friend, 95 Va. 135-6, 27 S. E. 901; Richmond Traction Co. v. Clarke, 101 Va. 392, 43 S. E. 618, and Gatewood v. Garrett, 106 Va. 554, 56 S. E. 335.

These authorities do hold that, where a party is granted instructions upon the theory that there is, or is not, evidence in the case bearing on á certain question, he is estopped from denying that there is, or is not, as the case may be, any evidence whatever on the subject of the instruction. But that falls far short of holding that such party is, after verdict, precluded from making a motion to set aside the verdict on the ground that it is contrary to the evidence, or without sufficient evidence to support it. And such authorities have no application where, as in the instant case, the instruction is upon the subject of the cause of the injury complained of, and there is evidence upon that subject, but that evidence leaves it equally probable that the injury was due to some one of two or more causes, for only one of ■ which the defendant is liable. In such case it is the lack of any preponderance of.evidence to support the verdict which leaves it without sufficient evidence to support it.

The case under review must be affirmed.

Affirmed.

dissenting:

I find myself nnable to eoncnr in the opinion of the court delivered by Judge Sims.

In the view I take of the case, it will be unnecessary to consider all the questions raised by the assignment of error.

George D. Whipple, the plaintiff in error, who will be called the plaintiff, brought this suit in the Circuit Court of the city of Norfolk on an accident insurance policy issued by the Fidelity and Casualty Company of New York, the defendant in error, who will be called the defendant, and was awarded a verdict for $5,000, with interest from February 20, 1920, till paid. On December 13, 1920, the court set aside the verdict of the jury, and, without ordering a new trial, entered a final judgment against the plaintiff in favor of the defendant, with costs. To that judgment this writ of error was awarded.

The policy is in the usual form, has been in force continuously since February 15, 1903, and insures the holder “against disability or death resulting directly, and independent of all other causes,' from bodily injuries sustained through external, violent and accidental means,” and provides that if, “irrevocable loss of the sight of both eyes shall so result from said injuries within ninety days, the company will pay the assured $5,000.00, which payment shall terminate the policy;” and further provides that “immediate written notice must be given the company at New York city of an accident and injury for which a claim is to be made, with full particulars thereof, and the full name and address of the assured. Affirmative proof of death, or loss of limb, or of sight, or of duration of disability, must also be furnished to the company within two *230months from the time of death, or of loss of limb, or of sight, or of termination of disability. Legal proceedings for recovery hereunder may not be brought till after three months from date of filing proofs at the company’s home office.”

On November 7, 1919, the plaintiff was eating some peanut brittle candy and while so doing the crown on one of the lower jaw teeth on the right side of his mouth was loosened and the tooth broken off, and, as a result thereof, it became and was necessary to have the remaining portion of the tooth removed, and in an effort to remove the same, and as a consequence thereof, the defendant became permanently and totally blind.

The plaintiff’s only assignment of error is to the action of the Circuit Court of the city of Norfolk in sustaining the defendant’s motion to set aside the verdict of the jury and enter judgment for the defendant.

The defendant contends that the action of the circuit court in so doing should be affirmed, for the following reasons:

I. There was no evidence showing any causal connection between the alleged accident and the defective eyesight of which the insured complained.

II. The plaintiff failed to show that the trouble with his eyesight amounted to blindness and that it became total and incurable within ninety days.

III. The plaintiff failed to show compliance with the provisions of the policy, either in respect to giving notice or furnishing proof.

IY. The injury complained of was not the result of an accident.

(a) Has the plaintiff failed to give notice and furnish proof, as required by the contract?

The policy provides that immediate, written notice must be given the company at New York city of any *231accident or injury “for which claim is to be made.” A substantial compliance with this provision of the contract is all that is required of the insured, and the company may by its conduct waive its right to rely upon plaintiff’s failure to give notice or furnish proofs, as provided in the contract.

The evidence shows that during the seventeen years this policy has been in force the insured has had several accidents and injuries for which he might have presented a claim but declined to do so, and that the reason he did not notify the company earlier was the hope that he would regain his sight,' in which event he did not expect to present any claim for this injury.

Insurance contracts should be liberally construed in favor of the insured, and under a fair construction of the notice clause in the policy the insured was not required to give notice of the accident and injury until it was apparent that the injury was one for which a claim was to be made. And, in case of partial disability, the proof of loss of sight, or duration of the disability was only required to be furnished within two months from the termination of the disability. As soon as the plaintiff realized the serious, permanent condition of his eyes, he at once notified the company’s representative and the company. He wrote the company’s agent on February 11, 1920, and the company on February 21, 1920. The company replied on March 6, 1920, enclosing preliminary report and accident claim blank; and on March 11, 1920, plaintiff wrote the company giving a detailed account of the accident and injury and the then condition of his eyes. Upon receipt of this information, the defendant gave no intimation that it would rely upon the failure of the plaintiff to give notice in time, but soon thereafter sent its investigator, Mr. Sharp, to see the plaintiff, who gave him a complete history of the case.

*232The plaintiff had decided to go to see a physician somewhere out of Norfolk, but Sharp, after talking with all the doctors who had been consulted by the plaintiff, requested the plaintiff to postpone his going away until he could bring a specialist representing the company to Norfolk to see him. In order to comply with the company’s request in this respect, the plaintiff ceased his activity in prosecuting his claim and postponed treatment by a specialist, who might have, at that time, in some measure, relieved his deplorable condition.

The company’s specialist never made his appearance, but, Investigator Sharp, after waiting some time, returned and told the plaintiff that the company denied liability, not on account of the plaintiff’s failure to give notice of the accident, but because there was no accident which caused the plaintiff’s blindness. It appears from the evidence that the defendant at no time prior to the institution of this suit made any objection to the plaintiff’s delay in giving notice or furnishing proof.'

It is said by the United States Supreme Court in Railway Co. v. McCarthy, 96 U. S. 258, 24 L. Ed. 693: “Where a party gives a reason for his conduct and decision touching anything involved in a controversy, he cannot, after litigation has begun, change his ground, and put his conduct upon another and different consideration. He is not permitted thus to mend his hold. He is estopped from doing it by a settled principle of law.”

In Traveler's Ins. Co. v. Harvey, 82 Va. 949, 5 S. E. 553, this court held that when an insurance company refuses to recognize any claim, such refusal waives compliance' with the conditions as to preliminary notice and proof and authorizes immediate suit.' This ruling is manifestly fair to the company and is supported by the leading authorities on insurance contracts. •

*233In May on Insurance, page 649, the writer says: “A distinct denial of liability, and refusal to pay, on the ground that there is no contract, or there is no liability, is a waiving of the condition requiring proof of loss. It is equivalent to a declaration that they will not pay, though the proof be furnished, and to require the presentation of proof in such a case, when it can be of no importance to either party, and the conduct of the party in favor of whom the stipulation is made has rendered it practically superfluous, is but an idle formality, the observance of which the law will not require. * * * And a waiver of the proof is a waiver of the condition that payment is not to be made until a limited time after the proof, so that in such case suit may be brought at once upon the denial of liability, although the time within which, after proofs of loss, the payment would be demandable may not have expired.

And in Flanders on Fire Insurance, at page 542, it is said: “The refusal to recognize the evidence of any claim, or a general refusal to pay, renders the delivery of notice and proofs a useless ceremony, and is treated as waiving a strict compliance with the condition as to the preliminary notice and proof, both in respect to form and time.”

The New York court held in Trippe v. Provident Fund Society, 140 N. Y. 23, 35 N. E. 316, 22 L. E. A. 432, 37 Am. St. Rep. 529, that where a notice of a death by accident is given at a later day than stipulated in the policy, but is retained without objection, and the insurer furnished blank proofs of loss, and on being filled out and forwarded, also retains them without objection, and subsequently demands furthér information, which is furnished, the insurer waives the objection that the notice was not given in time'. The policy in question is a New York contract, entered into by the plaintiff while *234he was a citizen of New York, and the notice is to be given in New York. Under these circumstances, the ruling of the New York court upon a construction of the notice clause in the contract is controlling in the instant case.

In Mullen v. Read, Guardian, 64 Conn. 240, 29 Atl. 478, 24 L. R. A. 664, 42 Am. St. Rep. 174, a suit to recover on a life insurance policy issued in Massachusetts, it was held that the contract should be interpreted and construed according to the decisions of the courts of Massachusetts, where the contract was made and was to be performed.

By the weight of authority, and on principle, where the parties have assented to a writing as an expression of their agreement, the standard of interpretation is the local standard. 2 Williston on Contracts, section 607.

In 1 Am. & Eng. Ency. Law & Practice, at p. 387, we find the law stated thus: “Questions frequently arise as to a waiver by the insurer of a failure to give notice of the injury or to furnish proofs of injury or death within the time specified in the policy; and it has been held that in the absence of express waiver some element of estoppel must exist, and that it must be shown that the insured was reasonably misled to this prejudice by some act or declaration of the insurer or its duly authorized agent. However, a technical estoppel is not necessary, it being sufficient if the declarations or conduct of the insurer, subsequent to the breach of the condition, indicate an intention to waive or not to rely on the condition, and the insured or beneficiary is thereby induced to remain inactive, or to incur some trouble or expense; and very slight circumstances are sufficient to establish a waiver of the condition.”

The defendant by its conduct, and demand for time in which to bring forward the company’s specialist, *235caused the plaintiff to be inactive and to occupy a more disadvantageous position than he would have occupied but for the conduct of the defendant in these respects.

It follows from what has been said that if the plaintiff has failed to substantially comply with the provisions of the policy contract as to notice and proof, which I do not admit, the defendant, by its conduct, has waived the right to demand a strict compliance with the conditions of the policy as to preliminary notice and proof.

(b) Was the injury complained of the result of an accident?

The plaintiff’s condition could only be brought about by accident, or disease. It appears from the evidence that he was a man fifty-one years old, in robust health and enjoying perfect vision. He was subjected to no medical or surgical treatment which could have affected his eyesight other than that incident to the treatment of his tooth, which was advised by his dentist, and it is not claimed that the dentist who did this work did not do it in a scientific and proper manner.

It is not contended that the breaking of the tooth did not render' dental and medical treatment necessary, and, if the treatment resulted in the injury, the accident and not the treatment was the cause of the injury. If a person carries accident insurance and his leg is accidentally injured so seriously as to necessitate amputation, and the act of amputation so shocks his nervous system as to cause his death, it could not be said that the accident was not the cause of his death.

The case of Travelers’ Insurance Company v. Melick, 65 Fed. 178, 12 C. C. A. 544, 27 L. R. A. 629, was a suit on an accident policy with the provision that injury should result “through external, violent and accidental means alone.” The insured accidentally shot himself in the foot, and as a result of the wound thereby *236created tetanus resulted, and while under the influence of a tetanic spasm he cut his throat with suicidal intent. The policy expressly exempted the company from liability for death by suicide. The court held that the cause of death was directly due to the original accidental gunshot wound and not to the act of insured in cutting his own throat while under the influence of that wound accidentally created.

When an injury is caused by means insured against, and the medical treatment administered is rendered necessary and proper by the nature of the injury, the death of the insured, if caused solely by the injury and the subsequent medical treatment, is “accidental,” within the meaning of a policy insuring against death caused by “external, violent and accidental means.” Gardner v. United Surety Co., 110 Minn. 291, 125 N. W. 264, 26 L. E. A. (N. S.) 1004.

In Westmoreland v. Preferred Accident Ins. Co. (C. C.), 75 Fed. 246, it was held that if an accident rendered necessary medical treatment, and the treatment resulted in an injury, the accident and not the treatment was the cause of the injury. 'It follows that the plaintiff’s injury was the result of an accident.

(c) Was there any evidence showing any causal connection between the accident and the defective eyesight of which the plaintiff complained?

The undisputed testimony of the plaintiff is that prior to the extracting of the root of the tooth he was a strong, active man, in the enjoyment of very good health, in the possession of all his faculties, and h.ad all his life enjoyed unimpaired eyesight; that immediately after the doctor made an effort to extract the remaining portion of the tooth he had violent pains in his throat, face, head "and eyes; that his eyes felt like something was cutting 'them out and burning them; that these *237pains were simultaneous with the pains at the root of the tooth; that he had nó pain before the breaking off of the tooth; that when Dr. Warden, his dentist, put some applications in the socket of the tooth it would temporarily relieve the pain in his head, throat and eyes, as well as in the tooth; that the day the tooth was extracted he noticed his eyesight was impaired; that for nearly three weeks he suffered pain simultaneously in the tooth socket and in his eyes all the time, except when the doctor would quiet it; that while in pain, his eyesight would get dim, but, in the beginning of the treatment, when the doctor would quiet the pain his eyesight would temporarily improve; that his sight, notwithstanding the temporary improvement when the pain was relieved, gradually grew worse and continued to grow worse, even after all pain was relieved, until the last of December, when he could not see to write on his books.

While Dr. Warden stated that he did not attribute the plaintiff’s “difficulty in swallowing” to very much except possibly the anesthetic which had been administered, he did not say he attributed the plaintiff’s symptoms to the anesthetic, and he testified that when he would treat the tooth socket it would relieve the pain, not only at that location but also in his eyes, and that he continued these treatments two or three times a day for over two weeks.

Dr. Myers, the eye specialist, introduced as an expert witness for the defendant, who examined the plaintiff’s eyes, delivered quite a discourse on primary and secondary atrophy of the optic nerve and named numerous causes which could produce optic atrophy, but frankly admitted that it was possible that the optic atrophy of which the plaintiff was suffering was the result of the accident to his tooth, or the treatment of his tooth; and *238that he could not find anything from which the condition of his eyes resulted. There is nothing in his testimony which shows that the plaintiff had optic atrophy before the accident, or that the verdict of the jury was wrong, as will appear from the following questions and answers:

“Q. Do you know what caused the blindness?

“A. No, sir.

“Q. You won’t undertake to say under oath that it is impossible for it to follow from what has been narrated in the evidence here today?

“A. I would not.

“Q. You know of no disease he has at all, do you?

“A. No, I don’t.

“Q. Could you find anything from which you thought the condition which he complained of in his eyes did result? Could you trace it to any cause?

“A. I could not find any cause.”

Dr. Myers also caused a blood test to be made of the plaintiff’s blood to ascertain the presence of latent diseases, but found none. He then turned him over to an interne to be examined thoroughly, but this interne was never sworn as a witness for the defendant. The company’s specialist from a distance, to whom the plaintiff agreed to submit for an examination, neither made an examination nor appeared as a witness for the defendant. It is fair to infer that the examination of the interne disclosed nothing which would sustain the defendant’s theory of the case, and that the defendant reached the conclusion that its defense would not be strengthened by an examination made by its own specialist.

The defendant’s position, in effect, is, that the plaintiff cannot recover because he failed to introduce a medical witness who would give opinion evidence to the ef*239feet that the violent pains, which resulted from extracting the roots of the tooth and were communicated to his eyes, caused his eyesight to become impaired to such an extent as to produce total blindness. In this contention I cannot concur.

Of course, there are cases involving highly technical questions, where the jury must rely upon expert testimony, as in cases of malpractice, in which the only way to prove a want of skill on the part of medical practitioners is by expert evidence. And it will be observed that most of the cases cited by the defendant to sustain its position on this point belong to this class.

The cases of Ewing v. Goode (C. C.), 78 Fed. 442; Hunter v. Burroughs, 123 Va. 113, 96 S. E. 360, and Robbins v. Nathan, 189 App. Div. 827, 179 N. Y. Supp. 281, relied on strongly by the defendant, were all cases of alleged malpractice.

In Ewing v. Goode, supra, Judge Taft says: “In many cases expert evidence, though all tending one way, is not conclusive upon the court and jury, but the latter, as men of affairs, may draw their own inferences from the fact's, and accept or reject the statements of experts; but such cases are where the subject of discussion is on the border line between the domain of general and expert knowledge * *

The test of the sufficiency of the circumstances adduced always is, that, viewed as a whole, they reasonably exclude, by their preponderating probative weight, any other explanation based on the evidence. Phila. Trust Co. v. Phila., etc., R. R. Co., 160 Pa. 590, 28 Atl. 960.

It was held by the court in C. & O. Ry. Co. v. Catlett, 122 Va. 232, 94 S. E. 934, that “in civil cases the reasoning to establish a fact is not required to measure up to the exclusion of every other hypothesis consistent with *240the evidence; that it is required only that the fact considered as established be the more probable hypothesis from the evidence with reference to other hypotheses predicated upon the evidence — that is to say, in civil cases, a fact may be established by a preponderance only of the evidence. But the preponderance of the evidence rule does not dispense with the requirement that there must be some evidence which has some logical probative value to establish a fact, before that fact can be even considered as a possible hypothesis predicated upon the evidence — a fortiori, before it can be considered as the more probable hypothesis from the evidence.”

It follows that the plaintiff was not required to prove that he was free from every form of disease which could have caused the atrophy, but was only required to satisfy the jury that it was more probable from the evidence that the atrophy was caused by the accident to or medical treatment of the tooth, than from any other cause predicated upon the evidence; and to so satisfy them with evidence which has some logical probative , value. This the plaintiff has done.

The previous good health and perfect vision of the plaintiff, the repeated recurrence and concurrence of the pain and the dimness of sight as long as the pain lasted, covering a period of over fifteen days, during which time the impairment of the sight was increasing, the reasonable inference that the optic nerve had become so diseased by the shock and pain that the plaintiff’s sight continued, as a result thereof, to grow worse after the pain had subsided, and the fact that Dr. Myers, the eye specialist, upon an examination of plaintiff’s eyes, could find nothing to make him think the optic atrophy was in existence before the accident, are facts and circumstances of logical probative value which *241reasonably exclude, by their preponderating probative weight, any other explanation, based upon the evidence, than that the plaintiff’s blindness resulted from the accident to or necessary medical treatment of his tooth, and furnish prima facie proof which has not been rebutted that the optie atrophy was not in existence prior to the accident.

In order to ascertain whether there is any causal connection between the accident and the defective eyesight we need, not the opinions of additional experts, but simply to give due weight to the other evidence in the case and apply the everyday method of reasoning, that effect always follows from cause. The positive uncontradicted testimony of the plaintiff is that when he had pain in the cavity of the tooth, he had pain in his eyes, which impaired his sight, and when by local treatment the pain in the cavity was allayed the pain left his eyes and his sight was, at first, temporarily improved, but grew worse each time, and finally when the pain subsided the optie nerve was so much diseased that the impairment of sight increased until it resulted in his total blindness. Add to these facts the fact of the previous good health and perfect vision of the plaintiff and the lack of any other. cause to which impaired vision could be attributed, and the statement by Dr. Myers that optic atrophy may be caused without contact with the optic nerve by blow or physical shock, and that the extracting of the tooth might possibly have produced optie atrophy, and it cannot be said that the verdict of the jury, finding that the breaking of the tooth and the subsequent medical treatment thereof were the cause of the injury complained of was plainly wrong, or without evidence of probative value to support it.

The fact that the dimness of the sight did not retain its improvement after the pain had been entirely re*242lieved does not, as contended by the opinion by Judge Sims, destroy the reliance to be placed on the correctness of the conclusion that the repeated concurrence of cause and effect tends to prove that that relationship existed, since it plainly appears from the evidence that, notwithstanding the temporary improvement of the sight when the pain was temporarily allayed, the impairment of the sight greatly increased during the fifteen days the tooth socket was treated for the pain, and the reasonable inference is that the optic nerve had become so much diseased, as a result.of the shock and pain, that it continued from that cause to grow worse, rather than better, after the pain had completely subsided.

(d) Does the evidence show that the trouble with plaintiff’s eyesight amounted to blindness, and that it became total and incurable within ninety days?

The plaintiff testified that he could do a few things the last of December, but about the ,10th or 12th of January he had to give up. His son testified that the only clerical work the plaintiff could do about January 1, 1920, was to endorse checks and drafts by his directing his hand, and that he could not do this unassisted. Ge.o. S. Whipple, his son, also testified that on February 1st, following the accident, plaintiff did not recognize him until he spoke, although he was in front of him with his hand on his arm.

H. M. Kirby testified that plaintiff, comes to his office and buys cigars and he can’t tell silver money, except by the notches on it, with his finger nails. This is peculiarly a case for the jury. They saw the plaintiff on the witness stand; and the facts' and circumstances surrounding the ease were sufficient to warrant the jury in reaching the conclusion that his blindness became total and incurable within ninety days.

By asking for instruction No. 1, the defendant seems *243to have recognized the existence of evidence which, if the jury believed it, would sustain a verdict for the plaintiff.

Instruction No. 1, given at its request, was as follows: “The plaintiff cannot recover unless they believe from the evidence that he is totally and permanently blind in both eyes, and that such loss of sight is irrecoverable and resulted directly and independently of all other causes, from external, violent and accidental means within ninety days from the date at which said injuries were sustained, and that immediate written notice of the accident was given the defendant at its home office in New York with full particulars, and affirmative proof of the loss of sight furnished the defendant within two months from such loss of sight, unless the jury shall find from the evidence that the giving of such notice and such proof of loss of sight were waived by the conduct of the company.”

By the foregoing instruction, at defendant’s request, the court submitted to the jury the questions of waiver by the company of notice and proof of loss, of plaintiff’s total and incurable blindness, and whether, if it existed, the same resulted from external, violent and accidental means within ninety days of date of injuries.

In Spicer v. Webster City, 118 Iowa, 561, 92 N. W. 884, we find this: “A city in an action against it for injuries requested an instruction which submitted the issue whether it had actual notice of the defect, and the court submitted such question to the jury by an interrogatory, which was answered in the affirmative. It was held on appeal that the city, by requesting the instruction in question, could not complain that the answer to the interrogatory was unsupported by evidence. This would seem to be not only common sense, but simple justice.”

*244In Kimball & Fink v. Friend’s Adm’r, 95 Va. 135, 136, 27 S. E. 902, this court said: “By the third instruction given for the plaintiff, the jury were instructed that if the defendants could in the result, by the exercise of ordinary care and diligence, have avoided the accident, the negligence of the plaintiff’s intestate would not excuse the railroad company. This instruction is objected to on the ground that there was no evidence tending to show that the accident could have been avoided after the peril of the deceased was discovered. * * * *

“Not only did the plaintiff and the court think that there was evidence tending to prove the facts upon which that instruction was based, but the defendants admitted (and now are estopped from denying) that there was such evidence by asking the court in their fourth instruction to tell the jury that if they believed certain facts they must find for the defendants, ‘unless they further believe that after perceiving the negligence of the plaintiff’s intestate, they could have avoided the effect of such negligence by the exercise of ordinary care.’ ”

In Gatewood v. Garrett, 106 Va. 554, 56 S. E. 336, the court makes this statement: “It is true that the instruction could not be considered if the existence of the evidence upon which it rests could only be ascertained by looking at the imperfect certificate of such evidence found in the record; but where the plaintiff has asked for instructions which are plainly predicated on the existence of such evidence, he is estopped from denying its existence.”

A party is estopped to complain of the judgment for insufficiency of evidence to sustain it when, on the trial, he supplied the deficiency by his own evidence; or he admitted the existence of the facts which such evidence *245would, have established, either by asking an instruction based thereon, or by stipulation, or by concession. 3 Cyc. 246.

Instruction No. 1 told the jury the plaintiff could not recover unless they believed from the evidence certain facts, and they returned a verdict for the plaintiff. Having taken the position that there was evidence upon which the jury might rest such a verdict, the defendant cannot now be heard to deny the existence of such evidence.

The weight of the evidence and the credibility of the witnesses were questions for the jury. The evidence in the record was ample to support this verdict, and the circuit court should not have set it aside.

For the foregoing reasons, I am of the opinion that the judgment complained of is erroneous and should be reversed, and judgment entered here in favor of the plaintiff against the. defendant for the amount ascertained by the jury, with interest and costs.

dissenting:

In my view of the evidence, the question whether the plaintiff’s blindness more probably resulted from the accident than from some other cause was one which addressed itself to the jury, and for this reason I am unable to concur in the opinion of the court.