Where these latter rights are not specifically granted by statute, the rule has been established by the courts that they will be upheld so far as necessarily inferable from the rights granted and not further. It is under this rule that the greater number of the mooted questions in the application of copyright law have arisen in respect to the scope of copyright. Most of these specific rights are in fact necessary inferences from the statute, in the protection of the property rights therein conferred, but the courts will not go beyond fair construction of the letter of the statute. {Sidenote: Differentiated contracts} In respect to the rights to give, lend, grant, manufacture, lease or license, mortgage or devise copyright property, it may be said that these are subsidiary rights conditioned on and essential to the general right of property in copyrightable or copyrighted material. An author may exercise any of these rights in respect to his unpublished work so far as they are applicable to it, or to his copyrighted work after publication; and either the copyrightable manuscript or the copyrighted work may pass by inheritance. Thus an author may manufacture, or cause to be manufactured, his unpublished work, and he may retain exclusive control over the manufactured copies so long as he pleases before publishing the work; and after publication (which involves placing on public sale, or publicly distributing) he may exercise these rights negatively by withdrawing his work from further sale. The English law, however, contains a provision that in certain cases the Crown may require continuance of publication. {Sidenote: Enforcement in limited grants} In respect to the right to limit the use of his work under his sale, gift, loan, grant, lease, etc., for a special purpose or at a special price, or for a special time, or in a special locality or to a special person, these powers of limitation, though implied in the grant of copyright, are dependent for their enforcement rather upon the law of contracts than upon copyright law.