SECTION 1182 . Matter Unmailable Under Certain Conditions . — Matter otherwise of a mailable character may be unmailable for failure to comply with the conditions requisite for transmission through the mails or for the carriage of which the Bureau of Posts h as no adequate facilities. 

SECTION 1183 . Disposition of Nonmailable Matter . — All matter which is absolutely nonmailable by reason of its nature and which is deposited in any post office for transmission or delivery by mail, shall be forfeited to the Government. AcHEaS 

Matter unmailable under section one thousand one hundred and eighty-two, above, when deposited in any post office for transmission or delivery by mail, shall be returned to the person who so deposited it if his identity is known or can be ascertained, but shall not be forwarded or delivered to its addressee. aTcSID 

SECTION 1184 . Classes of Mail Matter which shall be Transmitted Free of Charge . — Official mail of officers of the United States Government, addressed for delivery in the Philippines, in the United States or any of its possessions, or at any United States postal agency, shall be received, transmitted, and delivered in the mails of the Philippine Islands free of ordinary postal charges when the outside envelope or wrapper thereof bears, over the words "Official Business", the name of the Department, and if i t is from a Bureau or Office, the name of such Bureau or Office, from whence transmitted, with the signature of the officer who offers it for transmission and a statement of the penalty for the misuse of such envelope or wrapper to avoid the payment of pos tage on nonofficial matter. This privilege shall not extend to any Department, Bureau, or Office of the Government of the Philippine Islands, except the Bureau of Posts. 

SECTION 1185 . Disposition of Dead Letters and Valuable Inclosures Therein . — Dead letters containing valuable inclosures shall be recorded in the dead-letter office; and when they cannot be delivered to the party addressed nor to the writer, the contents t hereof shall be disposed of, and a careful account shall be kept of the amount realized in each case, which shall be subject to reclamation by either the party addressed or the sender, for four years from the recording thereof after which it shall become a  part of the postal revenues. All dead letters and other mail matter not valuable which cannot be delivered to either addressee or sender shall be destroyed in the manner prescribed by the regulations of the Bureau. 

SECTION 1186 . Disposition of Undelivered Matter of the Second and Third Classes . — Second and third class mail matter shall not be returned to sender or remailed until the return postage has been fully prepaid on the same; but in all cases where undelivere d matter of these classes is of obvious value, the 

