pose which the law has in view in recognizing a change of title in any of these cases. That purpose is not to establish any arbitrary distinctions, based upon mere physical reasons, but to adjust the redress afforded to the one party and the penalty inflicted upon the other, as near as circumstances will permit, to the rules of substantial justice.

It may often happen that no difficulty will be experienced in determining the identity of a piece of timber which has been taken and built into a house; but no one disputes that the right of the original owner is gone in such a case. A particular piece of wood might perhaps be traced without trouble into a church organ, or other equally valuable article; but no one would defend a rule of law which, because the identity could be determined by the senses, would permit the owner of the wood to appropriate a musical instrument, a hundred or a thousand times the value of his original materials, when the party who, under like circumstances, has doubled the value of another man's corn by converting it into malt, is permitted to retain it, and held liable for the original value only. Such distinctions in the law would be without reason, and could not be tolerated. When the right to the improved article is the point in issue, the question, how much the property or labor of each has contributed to make it what it is, must always be one of first importance. The owner of a beam built into the house of another loses his property in it, because the beam is insignificant in value or importance as compared to that to which it has become attached, and the musical instrument belongs to the maker rather than to the man whose timber was used in making it, not because the timber cannot be identified, but because in bringing it to its present condition the value of the labor has swallowed up and rendered insignificant the value of the original materials. The labor, in the case of the musical instrument, is just as much the principal thing as the house is in the other case instanced; the timber appropriated is in each case comparatively unimportant.

No test which satisfies the reason of the law can be applied in the adjustment of questions of title to chattels by accession, unless it keeps in view the circumstance of relative values. When we bear in mind the fact that what the law aims at is the accomplishment of substantial equity, we shall readily perceive that the fact of the value of the materials having been increased a hundred fold, is of more importance in the adjustment than any chemical change or mechanical transformation, which, however radical, neither is expensive to the party making it, nor adds materially to the value. There may be complete changes with so little improvement in value, that there could be no hardship in giving the owner of the original materials the improved article; but in the present case, where the defendant's labor-if he shall succeed in sustaining his offer of testimony will appear to have given the timber in its present condition nearly all its value, all the grounds of equity exist which influence the courts in recognizing a change of title under any circumstances.

We are of opinion that the court erred in rejecting the testimony | offered. The defendant, we think, had a right to show that he had manufactured the hoops in good faith, and in the belief that he had the proper authority to do so; and if he should succeed in making that showing, he was entitled to have the jury instructed that the title to the timber was changed by a substantial change of identity, and that the remedy of the plaintiff was an action to recover damages for the unin-1 tentional trespass.

This view will dispose of the case upon the present record. Upon the other points we are not prepared to assent entirely to the views of the plaintiff in error. It does not appear to us important that the deed from Sumner to Camp and Brooks was intended as a mere security. Under such a deed Sumner would have had a right of redemption, but it does not follow that he would have been entitled to possession, and to all the other rights of mortgagor in the courts of law. When a deed absolute in form is given to secure a debt, the purpose generally is to vest in the grantee a larger power of control and disposition than he would have by statute under an ordinary mortgage; and we are not prepared to say that the statute - Comp. L. § 4614 - which forbids ejectment by mortgagees before foreclosure was intended to reach a case of that description. We think, however, that the mere circumstance of the sale of Sumner's interest did not operate in law as a revocation of the ! authority previously given to Sumner to sell the timber. It is quite possible that Green would not have given his authority had Sumner not been tenant in common of the land with him; but there is no absolute presumption of the law to that effect; and we cannot say that Green would have revoked the authority had he been aware of Sumner's conveyance. Nor was it necessary that the license given by Sumner to Wetherbee should have been in any particular form. A mere license to enter upon land and cut timber does not confer a legal right to do so; but it nevertheless protects the licensee so far as he has acted under it before revocation, and the protection does not depend upon its form, but upon what has been done having proceeded by consent. However informal the consent may have been, the land owner cannot be allowed, by afterwards recalling it, to make the licensee a trespasser for what he has done in reliance upon it.

For the reasons given, the judgment must be reversed, with costs, and a new trial ordered.

The other justices concurred.

company had knowledge of the cutting and hauling by the plaintiffs while it was in progress. After the mining company had taken possession of the wood, plaintiffs brought this suit. The declaration contains two special counts, the first of which appears to be a count in trover for the conversion of the wood. The second is as follows:

"And for that whereas also, the said plaintiff, Michael Hertin, was in the year 1874 and 1875, the owner in fee simple of certain lands in said county of Houghton, adjoining the lands of the said defendant, and the said plaintiffs were, during the years last aforesaid, engaged as co-partners in cutting, hauling and selling wood from said lands of said Michael Hertin, and by mistake entered upon the lands of the said defendant, which lands adjoined the lands of the said plaintiff, Michael Hertin, and under the belief that said lands were the lands of the said plaintiff, Michael Hertin, cut and carried away therefrom a large amount of wood, to wit: one thousand cords, and piled the same upon the shore of Portage Lake, in said county of Houghton, and incurred great expense, and paid, laid out and expended a large amount of money in and about cutting and splitting, hauling and piling said wood, to wit: the sum of two thousand dollars, and afterwards, to wit: on the first day of June, A. D. 1875, in the county of Houghton aforesaid, the said defendant, with force and arms, and without any notice to or consent of said plaintiffs, seized the said wood and took the same from their possession and kept, used and disposed of the same for its own use and purposes, and the said plaintiffs aver that the labor so as aforesaid done and performed by them, and the expense so as aforesaid incurred, laid out and expended by them in cutting, splitting, hauling

and piling said wood, amounting as aforesaid to the value of two thousand dollars, increased the value of said wood ten times and constituted the chief value thereof, by reason whereof the said defendant then and there became liable to pay to the said plaintiff, the value of the labor so as aforesaid expended by them upon said wood and the expense so as aforesaid incurred, laid out and expended by them in cutting, splitting, hauling and piling said wood, to wit: the said sum of two thousand dollars, and being so liable, the said defendant in consideration thereof, afterwards to wit: on the same day and year last aforesaid and at the place aforesaid, undertook, and then and there faithfully promised the said plaintiffs to pay unto the said plaintiffs the said sum of two thousand dollars, and the interest thereon."

The circuit judge instructed the jury as follows:

"If you find that the plaintiffs cut the wood from defendant's land by mistake and without any wilful negligence or wrong, I then charge you that the plaintiffs are entitled to recover from the defendant the reasonable cost of cutting, hauling and piling the same." This presents the only question it is necessary to consider on this record. The jury returned a verdict for the plaintiffs.

Some facts appear by the record which might perhaps have warranted the circuit judge in submitting to the jury the question whether the proper authorities of the mining company were not aware that the wood was being cut by the plaintiffs under an honest mistake as to their rights, and were not placed by that knowledge under obligation to notify the plaintiffs of their error. But as the case was put to the jury, the question presented by the record is a narrow question of law, which may be stated as follows: whether, where one in an honest mistake regarding his rights in good faith performs labor on the property of another, the benefit of which is appropriated by the owner, the person performing such labor is not entitled to be compensated therefor to the extent of the benefit received by the owner therefrom? The affirmative of this proposition the plaintiffs undertook to support, having first laid the foundation for it by showing the cutting of the wood under an honest mistake as to the location of their land, the taking possession of the wood afterwards by the mining company, and its value in the condition in which it then was and where it was, as compared with its value standing in the woods.

We understand it to be admitted by the plaintiffs that no authority can be found in support of the proposition thus stated. It is conceded that at the common law when one thus goes upon the land of another on an assumption of ownership, though in perfect good faith and under honest mistake as to his rights, he may be held responsible as a trespasser. His, good faith does not excuse him from the payment of damages, the law requiring him at his peril to ascertain what his rights are, and not to invade the possession, actual or constructive, of another. If he cannot thus protect himself from the payment of damages, still less, it would seem, can he establish in himself any affirmative

rights, based upon his unlawful, though unintentional encroachment upon the rights of another. Such is unquestionably the rule of the common law, and such it is admitted to be.

It is said, however, that an exception to this rule is admitted under certain circumstances, and that a trespasser is even permitted to make title in himself to the property of another, where in good faith he has expended his own labor upon it, under circumstances which would render it grossly unjust to permit the other party to appropriate the benefit of such labor. The doctrine here invoked is the familiar one of title by accession, and though it is not claimed that the present case is strictly within it, it is insisted that it is within its equity, and that there would be no departure from settled principles in giving these plaintiffs the benefit of it.

The doctrine of title by accession is in the common law as old as the law itself, and was previously known in other systems. Its general principles may therefore be assumed to be well settled. A wilful trespasser who expends his money or labor upon the property of another, no matter to what extent, will acquire no property therein, but the owner may reclaim it so long as its identity is not changed by conversion into some new product. Indeed some authorities hold that it may be followed even after its identity is lost in a new product; that grapes may be reclaimed after they have been converted into wine, and grain in the form of distilled liquors. Silsbury v. McCoon, 3 N. Y. 379. See Riddle v. Driver, 12 Ala. 590. And while other authorities refuse to go so far, it is on all hands conceded that where the appropriation of the property of another was accidental or through mistake of fact, and labor has in good faith been expended upon it which destroys its identity, or converts it into something substantially different, and the value of the original article is insignificant as compared with the value of the new product, the title to the property in its converted form must be held to pass to the person by whose labor in good faith the change has been wrought, the original owner being permitted, as his remedy, to recover the value of the article as it was before the conversion. This is a thoroughly equitable doctrine, and its aim is so to adjust the rights of the parties as to save both, if possible, or as nearly as possible, from any loss. But where the identity of the original article is susceptible of being traced, the idea of a change in the property is never admitted, unless the value of that which has been expended upon it is sufficiently great, as compared with the original value, to render the injustice of permitting its appropriation by the original owner so gross and palpable as to be apparent at the first blush. Perhaps no case has gone further than Wetherbee v. Green, 22 Mich. 311, in which it was held that one who, by unintentional trespass, had taken from the land of another young trees of the value of $25, and converted them into hoops worth $700, had thereby made them his own, though the identity of trees and hoops was perfectly capable of being traced and established.