The opinion of the court was delivered,
by Lowrie, C. J.We are to assume that it was by mistake that the defendant below went beyond his line in mining his coal, and mined and carried away some of the plaintiff’s coal, and it is fully settled that for this trover lies: 3 S. & R. 515; 9 Watts 172; 8 Barr 294; 9 Id. 343; 9 Casey 251.
What, then, is the measure of damages ? The plaintiff insists *295that, because the action is allowed for the coal as personal property, that is, after it had been mined or severed from the realty, therefore, by necessary logical sequence, she is entitled to the value of the coal as it lay in the pit after it had been mined; and so it was decided below. It is apparent that this view would transfer to the plaintiff all the defendant’s labour in mining the coal, and thus give her more than compensation for the injury done.
Yet we admit’ the accuracy of this conclusion, if we may properly base our reasoning on the form, rather than on the principle or purpose of the remedy. But this we may not do; and especially we may not sacrifice the principle to the very form by which we are endeavouring to enforce it. Principles can never be realized without forms, and they are often inevitably embarrassed by unfitting ones; but still the fact that the form is for the sake of the principle, and not the principle for the form, requires that the form shall serve, not rule, the principle, and must be adapted to its office.
Just compensation in a special class of cases is the principle of the action of trover, and a little study will show us that it is no unyielding form, but adapts itself to a great variety of circumstances. In its original purpose, and in strict form, it is an action for the value of personal property lost by one and found by another, and converted to his own use. But i,t is not thus restricted in practice; for it is continually applied to every form of wrongful conversion, and of wrongful taking and conversion, and it affords compensation not only for the value of the goods, but also for outrage and malice in the taking and detention of them: 6 S. & R. 426; 12 Id. 93; 3 Watts 333. Thus form yields to purpose for the sake of completeness of remedy. Even the action of replevin adapts itself thus : 1 Jones 381. And so does trespass: 7 Casey 456.
In very strict form, trespass is the proper remedy for a wrongful taking of personal property, and for cutting timber, or quarrying stone, or digging coal on another man’s land and carrying it away; and yet the trespass may be waived and trover maintained, without giving up any claim for any outrage or violence in the act of taking: 3 Barr 13. It is quite apparent, therefore, that this form of action is not so uniform and rigid in its administration as to force upon us any given or arbitrary measure of compensation. It is simply a form of reaching a just compensation, according to circumstances, for goods wrongfully appropriated. When there is no fraud, or violence, or malice, the just value of the property is enough : 11 Casey 28.
When the taking and conversion are one act, or one continued series of acts, trespass is the more obvious and proper remedy; but the law allows the waiver of the taking, so that the party may *296sue in trover; and this is often convenient. Sometimes it is even necessary; because the plaintiff, with full proof of the conversion, may fail to prove the taking by the defendant. But when the law does allow this departure from the strict form, it is not in order to enable the plaintiff, by his own choice of actions, to increase his recovery beyond just compensation; but only to give -him a more convenient form for recovering that much.
Our case raises a question of taking by mere mistake, because of the uncertainty of boundaries; and we must confine ourselves to this. The many conflicting opinions on the measure of damages in cases of wilful wrong, and especially the very learned and thoughtful opinions in the case of Silsbury v. McCoon, 4 Denio 332, and 3 Comst. 379, warn us. to be careful how we express ourselves on that subject.
We do find cases of trespass, where judges have adopted a mode of calculating damages for taking coal, that is substantially equivalent to the rule laid down by the Common Pleas in this case, even where no wilful wrong was done, unless the taking of the coal out by the plaintiff's entry was regarded as such. But even then, we cannot avoid feeling that there is a taint of arbitrariness in such a mode of calculation, because it does not truly mete out just compensation: 5 M. & W. 351; 9 Id. 672; 3 Queen’s B. 283; and see 28 Eng. L. & E. 175. We prefer the rule in Wood v. Morewood, 3 Queen’s B. 440, n., where Parke, B., decided, in a case of trover for taking coals, that if the-defendant acted fairly and honestly, in the full belief of his right, then the measure of damages is the fair value of the coals, as if the coal field had been purchased from the plaintiffs. See also Bainbridge on Mines and Minerals 510; 17 Pick. 1.
Where the defendant’s conduct, measured by the standard of ordinary morality and care, which is the standard of the law, is not chargeable with fraud, violence, or wilful negligence or wrong, the value of the property taken and converted is the measure of just compensation. If raw material has, after appropriation and without such wrong, been changed by manufacture into a new species of property, as grain into whiskey, grapes into wine, furs into hats, hides into leather, or trees into lumber, the law either refuses the action of trover for the new article, or limits the recovery to the value of the original article : 6 Hill 425 and note; 21 Barbour 92; 23 Conn. 523; 38 Maine 174.
Where there is no wrongful purpose or wrongful negligence in the defendant, compensation for the real injury done is the purpose of all remedies; and so long as we bear this in mind, we shall have but little difficulty in managing the forms of actions so as to secure a fair result. If the defendant in this case was guilty of no intentional wrong, he ought not to have been charged with the value of the coal after he had been at the expense of *297mining it; but only with its value in place, and with such other damage to the land as his mining may have caused. Such would manifestly be the measure in trespass for mesne profits: 7 Casey •±56.
Judgment reversed, and a new trial awarded.
Read, J., dissented.