No United States newspapers of any kind or description (with the exception of exchange papers) are on any ground entitled to pass through the Canadian mails free of postage. [Sidenote: How to be forwarded from publication office.] In cities and towns where newspapers are published, the printers and publishers should send them to the post office put up in a manner to admit of their being readily counted, and if necessary withdrawn from their covers for examination. The newspapers for each office also should be made up in strong paper in a separate parcel, which should be plainly addressed. [Sidenote: Notification to publishers of non-delivery.] When the numbers of a newspaper published in Canada or in either of the other British North American Provinces, or in the United States, and issued daily, have remained in a post office in Canada uncalled for during two weeks; of a newspaper issued semi-weekly, or tri-weekly, during three weeks; of a newspaper issued weekly, during one month; and of a monthly periodical during two months, or when such newspapers and periodicals have been refused to be taken by the party to whom addressed, the postmaster is instructed to notify the respective publishers in the proper form, which is to pass free of postage. If the newspaper or periodical continues to arrive after the notice has been sent, the postmaster is instructed to notify the publisher in the same way a second time, specially calling his attention to the first notice given. [Sidenote: Enclosures in newspapers.] To enclose a letter, or any writing, or to make any written marks to serve the purposes of a letter, or to enclose any other thing (except publishers' accounts and receipts, as before mentioned) in a newspaper posted to pass as a newspaper, is a misdemeanor. Postmasters are requested at once to transmit all newspapers containing such writing, marks, and enclosures to the Postmaster General. <tb> PERIODICAL PUBLICATIONS. [Sidenote: Definition.] Periodical Publications are publications issued at regular intervals, but less frequently than once per week. [Sidenote: Rate to Canada and U. States.] Periodical Publications can be transmitted by post to any part of Canada and the United States at the following rates:-- For every periodical publication weighing not more than 3 oz. in weight .................................. 1 cent. Over 3oz. in weight .................................. 4 cents. 4 cents. [Sidenote: Pre-pay'mt] The above rates must invariably be pre-paid by postage stamps. [Sidenote: Sent from publication office.] If pre-paid by postage stamps and sent from the office of publication, periodicals published in Canada weighing over 3 oz. pass for two cents each. [Sidenote: From United States.]