Unless the letter is of the nature of privileged correspondence, the courts can probably require the production of a letter in court, and in fact do subpoena telegraph companies to produce the originals or transmittal records of telegrams in court, and thus make them quasi public property. The sale of a manuscript letter cannot authorize a vendee to publish it without consent of the writer, and the receiver of a letter is perhaps bound to keep a letter private or destroy it, if so required by the writer, but this is a right difficult of enforcement if not doubtful in esse. The receiver of a letter has probably a right to destroy it at his will, unless the writer has required its return to him.
The subject-matter of copyright in respect to musical and dramatic compositions and works of art, is treated specifically In later chapters on dramatic and musical copyright and on artistic copyright.
patentableDesigns for use in manufacture are, in the United Designs States, subjects of patent and not copyright. It is patentable provided by the act of May 9, 1902, that "any new, original, and ornamental design for an article of manufacture" may be patented, and this classification inferentially excludes such designs from copyright. This generalized description of design patents replaced, at the suggestion of the Commissioner of Patents, the specific descriptions in the design patents act of December 1, 1873, and adopted instead the more comprehensive phraseology of the act of February 4, 1887, for the punishment of infringement of design patents. In like manner the new British code excludes designs registrable under the patents and designs act, 1907, "except designs which, though capable of being so registered, are not used or intended to be used as models or patterns to be multiplied by any industrial process."