The first error assigned, on which the plaintiff in error, the defendant below, relies, is that the county court omitted to charge the jury that the burden was on the plaintiff below, of proving that when the injury complained of was committed, he was in the exercise of reasonable care and prudence. We accord, entirely, with the decisions,' cited by him to show that, in this suit, the burden of showing that the injury was not attributable to the want of reasonable care on his part, rested on the plaintiff The reason of this rule is, that the plaintiff must prove all the facts which are necessary to entitle him to recover, and this is one of those facts. It was necessary for the plaintiff to prove, first, negligence on the part of the defendant, in respect to the collision alleged, and, secondly, that the injury to'the plaintiff occurred in consequence of that negligence. But in order to prove this latter part, the plaintiff must show that such injury was not caused, in whole, or in part, by his own negligence; for, although the defendant was guilty of negligence, if the plaintiff’s negligence contributed essentially to the injury, it is obvious that it did not occur by reason of the defendant’s negligence. Therefore the plaintiff would not prove enough to entitle him to recover, by merely showing negligence on the part of the defendant; but he must go further and also prove the injury to have been caused by such negligence, by showing a want of concurring negligence on his own part, contributing materially to the injury. Hence, to say that the plaintiff must show the latter, is only saying that he must show that the injury was owing to the negligence of the defendant. And as the defendant had a right to have the jury informed, as to what facts the plaintiff must prove in order to recover, he had a right to require the court to instruct them, that it was incumbent on the plaintiff to prove a want of such concurring *346negligence on his part. But we are of opinion that this instruction was given substantially by the court below, and in such a manner that the jury could not have mistaken its import. The plaintiff, in making out his case, offered evidence to prove, and claimed to have proved, that when the injury occurred, he was in the exercise of reasonable care and prudence in the management of his horse. He assumed the burden of proving that fact; and when he had rested, this proof was met by evidence introduced by the defendant, tending to disprove, and claimed by him to disprove, such care and prudence on the part of the plaintiff. Upon this part of the case, after the evidence was closed, the defendant requested the court to charge the jury that the plaintiff could not recover, if they should find that he was guilty of negligence, which contributed essentially to produce the injury; and the court charged the jury as requested by the defendant, and also, that in order to determine whether the plaintiff exercised reasonable care, and prudence, they might take into consideration the character, disposition and temper of the plaintiff’s horse, and the manner in which he had been trained, as well as all the other circumstances attending the transaction. We think that the jury could not have failed to understand from this charge, in connection with the evidence, on both sides, to which it alluded and was applied, that if the evidence of the plaintiff did not show, or that of the defendant disproved, that the injury was not caused by the want of reasonable care, on the part of the plaintiff, the latter could not recover. The defendant therefore had the benefit, in the charge, of the rule which he requested the court to express to the jury, although not in the precise words in which he requested the court to express it.
The next error assigned, which is relied on by the plaintiff in error, is that the county court did not instruct the jury that, it being admitted that the horse of the plaintiff was a spirited animal, the act of the plaintiff in leaving him unfastened and unattended, was, as a matter of law, a want of *347ordinary care on his part, but left it to the jury, as a question of fact for them to determine, from the evidence, whether the plaintiff was, in this respect, guilty of negligence. We have no doubt that this course was correct. The question, as to the existence of negligence, or a want of ordinary care, is one of a complex character. The inquiry, not only as to its existence, but whether it contributed with negligence on the part of another, to produce^ a particular effect, is much more complicated. As to both, they present, from their very nature, a question not of la\y, but of fact, depending on the peculiar circumstances of each case, which circumstances are only evidential of the principal fact, that of negligence or its effects, and are to be compared and weighed by the jury, the tribunal whose province it is to find facts, not by any artificial rules, but by the ordinary principles of reasoning ; and such principal fact must be found by them, before the court can take cognizance of it, and pronounce upon its legal effect. This is in accordance with, and indeed is only a repetition of, our decision in Beers v. The Housatonic Railroad Company, 19 Conn. R., 566. If the circumstances, tending to prove negligence, such as was here imputed to the plaintiff below, could, as matter of law, be deemed to constitute or prove such negligence in any case, it is obvious that in the present one, we have not before us the circumstances, or evidence, which the bill of exceptions states to have been adduced on the trial, on that question, by either of the parties, and therefore we have not the means of determining whether the county court erred on this subject, unless we are prepared to say, what indeed the plaintiff in error virtually claims, that the leaving of a spirited horse attached to a carriage, with no other knowledge of his disposition, habits or character, unfastened and unattended by a person, at any time, or in any place, or for any purpose, or for any period of time, or indeed under any circumstances, is to be pronounced, as a conclusion of law, to constitute a want of ordinary care; a proposition which is manifestly absurd. *348The argument of the plaintiff in error, in favor of the practicability and propriety of treating the question of negligence as one of law, rather than of fact, is not aided by his reference to that class of decisions in actions upon commercial paper, where courts have pronounced upon the question of reasonable notice of its dishonor, as one of law. They apply only to a very peculiar class of mercantile contracts, and proceed on reasons, founded partly on public policy, and partly on the custom of merchants; principally, perhaps, on such custom, which constitutes the law merchant, by which such contracts are governed, and which has been ascertained by courts, to be in accordance with the arbitrary or artificial rules, which have been as a part of the law merchant, on the subject of such paper, adopted and engrafted into the common law. Viewed in this light, they are plainly inapplicable to the case now before us.
The other grounds assigned for error have been abandoned, and are clearly untenable.
We therefore advise that a new trial should not be granted.
In this opinion the other judges concurred, except Ells-worth, J., who was disqualified.