18. That every officer, non-commissioned officer, musician, and private shall take and subscribe the following oath or affirmation, to wit: “I, A. B., do solemnly swear or affirm (as the case may be) that while I continue in the service I will bear true faith and yield obedience to the Confederate States of America, and that I will serve them honestly and faithfully against their enemies, and that I will observe and obey the orders of the President of the Confederate States, and the orders of the officers appointed over me, according to the Rules and Articles of War.”