may be simply and well defined as a permission. Thus, a permission to upon the land or enter the house of him who gives it, the permission accorded by a belligerent power to its own subjects or to those : the enemy to carry on a trade interdicted by war. and the permission granted by a state to its citizens to sell certain ware- or exercise certain callings, are familiar examples of licenses. The most common and important of these are licenses to keep a tavern, to sell spir-ituous liquor, to peddle out goods, to sell by auction, and the like. All of these are _ -erned and regulated exclusively by statutes in the different states. In each state. the amount by way of tax for the license, if any. the privileges conferred by it, and the precautions against abuse. are determined only by the judgment of the legislature. in reference to the wants or peculiar circumstances of its people. It is universally admitted that each state has full power to enact general police regulations for the preservation of the public health and morals, and for this purpose it may require persons proposing to fallow particular occupa-ons, where abuses are liable to creep in. to obtain a license from the proper public author-ity. When, however, a license fee is imposed for the purpose of regulation merely, it should not exceed in amount the cost of the license and of a proper proportion of the expense of enforcing the law: but a license fee may also be imposed for the purposes of revenue, and then it is a tax. and can only be limited by the needs of government and the legislative discretion.

For shipping licenses, see Shipping. - A mere and proper license to do anything upon or with one's property transfers no interest and vests no right. It simply authorizes, or so to speak pardons, an unlawful act. Being a mere permission, it is evident that a license cannot permit anything which the licenser himself cannot d<: - that if one permits another simply to go upon his land, the alienation of the land will necessarily extinguish the privilege. Further, it is clear that the benefit of a license is limited to him who receives it: for as the license transfers no property or interest, the licensee has nothing to assign. Finally, it is characteristic of a license that it rests wholly in the indulgence and will of the licenser, and is revocable at his pleasure. These are the incidents of every mere license; but if the license be supported by the grant of an interest, or be necessary to the enjoyment of a right, it attaches inseparably to it. and partakes of its incidents. It may not only cease to be revocable, but may become capable assignment. Thus, to borrow a familiar illustration, a permission to hunt in a park and to carry away the deer killed, is a license so far as it concerns the mere privilege of hunting: but it includes also a grant of the deer.

If in such a case the grant of the property be well made, the license is irrevocable. So if one make a sale or gift of a chattel which is situated on his land or in his shop, the license to remove, though not express, but implied in such a case by law. is yet irrevocable, because the licensee has an interest in the chattel which can only be enjoyed by taking it away. The enjoyment of a mere parol license cannot be pushed so far as to create an easement: for such a continuing interest in lands can be le-gally raised only by deed, that is. by a formal instrument under seal. So that when one licenses another, by a mere parol permission, to keep hay stacks on his land, or allows the licensee to dig a ditch across it. the privilege in both case- is equally revocable even though it have been executed by the licensee. An eas -ment would have been irrevocable, but that could have been created only by deed. But let it be supposed that one has. with another's permission, erected a building on the land of the latter: a revocation of the license in such a case would cause the licensee material injury, and in extreme cases a court of equity will sometimes interpose for the protection of the licensee.

Courts of law have generally adhered to the strict law doctrines: and. in respect to permanent structures, though there are - me decisions which regard the license as coextensive with the duration of the building to which it relates, yet the weight of authority is adverse to this view, and in favor of limiting the licensee's privilege to a right of entry and removal, as in the case of ordinary chattels. The more favorable decisions rest on the doctrine of equitable estoppel, which has been borrowed from the chancery practice, and now forms a means of remedying by common law many wrongs which otherwise would not fall within the range of the common law jurisdiction. The general rule then, in the United States as well as in England, respecting licenses which concern the enjoyment of interests in lands, maintains their revocability, no matter what may have been done in reliance upon them; and no matter whether the question arise between the original parties, or be complicated by conveyance to third persons. - In international law, licenses are permissions to carry on a trade interdicted during war. The power to grant them rests naturally with the sovereign; but in time of actual hostilities they may be immediately issued by generals or other high military or naval officers.

These licenses are liberally construed, but no advantage must be taken of the indulgence which they grant; as for example, by carrying a different kind of goods from that expressly permitted, or by changing, without the consent of the granting power, the person by whom the license was to be used; for, if it be not expressly transferable, the license is personal only. - In American constitutional law questions of conflict between state and federal authority sometimes arise in regard to licenses, but they are not often difficult of solution. Thus, it is clear that a license granted by federal authority, within the sphere of congressional power, must be paramount to any state law or state regulation; while, on the other hand, a state license to do what would conflict with any federal authority must be void. This subject received thorough examination in the case of Gibbons v. Ogden, 9 Wheaton's Reports, 1, in which a law of New York giving exclusive privileges in the public waters of that state was held void as conflicting with the power of congress over commerce. But when a license fee is imposed by federal authority for revenue purposes only, being but a tax, it interferes with nothing allowed or prohibited under state laws.

Thus, liquor dealers are now required to pay a federal license tax; but this does not license the sale of liquors in any state where it is forbidden, or relieve from any state requirement of license or other state regulation. It gives no permission to carry on the business, but taxes it if carried on. (License Tax Cases, 5 Wallace, 462.)