"The right of eminent domain, or inherent sovereign power, gives to the legislature the control of private property for public uses, _and for public uses only_.... So, lands adjoining New York canals were made liable to be assumed for the public use, so far as was necessary for the great object of the canals.... In these and other instances which might be enumerated, the interest of the public is deemed paramount to that of any private individual; and yet, even here, the constitutions of the United States and of most of the States of the Union have imposed a great and valuable check upon the exercise of legislative power, by declaring that private property should not be taken for public use without just compensation.... It undoubtedly must rest, as a general rule, in the wisdom of the legislature to determine when public uses require the assumption of private property; but if they should take it for a purpose not of a public nature, as if the legislature should take the property of A and give it to B, or if they should vacate a grant of property, or of a franchise, under the pretext of some public use or service, such cases would be gross abuses of their discretion, and fraudulent attacks on private right, and the law would clearly be unconstitutional and void." Concerning the construction of corporate powers Kent lays down the following rule: "The modern doctrine is to consider corporations as having such powers as are specifically granted by the act of incorporation, or as are necessary for the purpose of carrying into effect the powers expressly granted, and as having no other. The Supreme Court of the United States declared this obvious doctrine, and it has been repeated in the decisions of the State courts. No rule of law comes with a more reasonable application, considering how lavishly charter privileges have been granted. As corporations are the mere creatures of law, established for special purposes, and derive all their powers from the acts creating them, it is perfectly just and proper that they should be obliged strictly to show their authority for the business they assume, and be confined in their operations to the mode and manner and subject matter prescribed." As to the duties of common carriers he says: "As they hold themselves to the world as common carriers for a reasonable compensation, they assume to do and are bound to do what is required of them in the course of their employment, if they have the requisite convenience to carry and are offered a reasonable and customary price; and if they refuse without just ground, they are liable to an action."