Sullivan, C. J.
George W. Brott was charged with burglary and convicted. The court received as evidence of guilt the fact that bloodhounds, after being taken to the place where the *396crime Avas committed, appeared to trail the burglar to defendant’s house. The competency of this eAddence is the only question necessary to consider in disposing of the case. The.conduct of the dogs Avas, perhaps, rightly received, in connection Avith an admission made by Brott, as evidence tending to prove that he committed the crime charged in the information; but it was also received as proof of independent crimes which the state brought to the attention of the jury, to which the admission did not relate. The only evidence of these independent crimes was the inference afforded by the conduct of the dogs. If such evidence is incompetent the conviction can not stand. The argument of the attorney general is that the bloodhound has an exceptionally fine perception of scent; that, in following a trail and discriminating between smells, he seldom or never errs; and that knowledge of his extraordinary aptitude is so nearly universal that courts will act upon it without proof. The bloodhound has, of course, a great reputation for sagacity, and there is a prevalent belief that, in the pursuit and discovery of fugitive criminals, he is practically infallible. It is a commonly accepted notion that he will start from the place where a crime has been committed, folloAV for miles the track upon which he has been set, find the culprit, confront him, and, miraMle clictu, by accusing bay and mien, declare, “Thou art the man.” This strange misbelief is with some people apparently incorrigible. It is a delusion which abundant actual experience has failed to dissipate. It lives on from generation to generation. It has still the attractiveness of a fresh creation. “Time writes no Avrinkle on its broAv.” But it is, nevertheless, a delusion, an evident and obvious delusion. The sleuthhound of fiction is a marvelous dog, but Ave find nothing quite like him in real life. We repudiate utterly the suggestion that there is any common knowledge of the bloodhound’s capacity for trailing, which would justify us in accepting his conclusions as trustworthy under circumstances like those disclosed by the present .record. The burglary Avas committed on the morning of *397July 5, before daylight. The trailing did not commence until about five in the afternoon. In the meantime the trail, near the scene of the crime, had been walked over, closely paralleled, and crossed, directly and obliquely, perhaps, a hundred times. And the sun had been shining on it steadily for more than twelve hours. The situation the dogs had to deal with was an exceptionally difficult one, and it was, we think, reversible error to accept their conclusion as legal evidence of defendant’s guilt. To get a nearer and clearer view of the nature of the evidence erroneously admitted, let us consider closely what trailing is. The path of every human being through the world, at every step, from the cradle to the grave, is strewn with the putrescent excretions of his body. This waste matter is in process of decomposition; it is being resolved into its constituent elements and its power to make an impression on the olfactory nerves of a dog or other animal becomes fainter and fainter with lapse of time. Under favorable conditions, such as free exposure to air and sun, every compound particle is rapidly separated into its original parts and, when the dissolution is complete, its characteristic scent is gone. The bloodhound is endowed Avith a remarkably keen scent. He has great ability for differentiating smells. His method of trailing is simple and well understood. Particles of waste matter given off by a particular individual fall to the ground and, while undergoing chemical change, come in contact with the olfactory neiwes of the dog, and produce an impression which he is able to recognize, as distinct and different from all other impressions. Hence, for a short time, a man may be easily trailed in the woods, or in the open country, by the effluvia in his wake. But in a city, and after the lapse of considerable time, the trailing is obviously more difficult and often, manifestly, impossible. But difficulties do not deter the bloodhound from pursuing his business. He trails as best he can. He always folloAvs some scent, and he goes somewhere. Undoubtedly, nice and delicate questions are time and again presented to him for decision. But the con*398siderations that induce him, in a particular case, to adopt one conclusion rather than another can not go to the jury. The jury can not know whether the reasons on which he acted were good or bad, whether they were all on one side or evenly balanced, or whether his faith in the identity of the scent which he followed was strong or weak. In attempting to separate one smell from ten, twenty, fifty or a hundred similar smells with which it is intermixed and commingled, it is highly probable, if not quite certain, that the bloodhound undertakes a task altogether beyond his capacity. Like other dogs, he has his limitations and they must be recognized in courts of justice, if not elsewhere. That the conclusions of the bloodhound are, generally, too unreliable to be accepted as evidence in either civil or criminal cases, is, we believe, the teaching of that common knowledge and ordinary experience which we may rightfully bring to the examination of this subject. If such evidence were held to be legal evidence, it would, standing alone, sustain a conviction, and courts in this golden age of enlightenment, would now and again be under the humiliating necessity of adjudging that some citizen be deprived of his property, his liberty, or his life, because, forsooth, within twenty-four or forty hours after the commission of a crime, a certain dog indicated by his conduct that he believed the scent of some microscopic particles, supposed to have been dropped by the perpetrator of the crime, was identical, or closely resembled, the scent of the person who had been accused and put upon trial. There are, we know, some cases in this country which hold that this kind of evidence is competent, but, it seems, the judicial history of the civilized world is against them. The bloodhound is, we admit, frequently right in his conclusions, but that he is as frequently wrong, is a fact well attested by experience. What he does in trailing, may be regarded as the declaration of a disinterested party, but, so regarded, the authorities are opposed to its admission. It is unsafe evidence, and both reason and instinct condemn it.
*399The judgment is reversed, and the cause remanded for further proceedings.
Reversed.