[Inclosure No. 4.] HEADQUARTERS DEPARTMENT OF THE GULF, New Orleans, La., June 16, 1862.

Messrs. CTE. MEJAN, French Consul; JUAN CALLEJON, Consul de Espana; JOSEPH DEYNOODT, Consul of Belgium; N. M. BENACHHI, Greek Consul; JOSEPH LANATA, Consul of Italy; B. TERYAGHI, Vice-Consul; AL. PIAGET, Swiss Consul:

GENTLEMEN: Your protest against General Orders, No. 41, has been received.

It appears more like a labored argument in which the imagination has been drawn on for the facts to support it. Were it not that some of the idiomatic expressions of the document show that it was composed by some one born in the English tongue, I should have supposed that many of the misconceptions of the purport of the order which appear in the protest arose from the imperfect acquaintance with the peculiarities of our language. As it is, I am obliged to believe that the faithlessness of the Englishman who translated the order to you and wrote the protest will account for the misapprehensions under which you labor in regard to its terms.

The order prescribes, first, a form of oath to be taken by those who claim to be citizens of the United States, and those only, who desire to hold office, civil or military, under the laws of the United States, or who desire some act to be done in their favor by the officers of the United States in this department other than protection from personal violence, which is afforded to all. With that oath, of course, the alien has nothing to do. But there is a large class of foreign born persons here, who, by their acts, have lost their nationalities. Familiar examples of that class are those subjects of France (Francais) who, in contravention of the "code civile," have, without authorization by the Emperor, joined themselves to (the) a military organization of a foreign State (s"affilierait a une corporation militaire etrangere) or received military commissioners (functions publiques conferees par un government entranger) from the Governor thereof, or who have left France without intention of returning (sans esprit de retour) or, as in the case of the Greek consul, have taken the office of opener and examiner of letters inthe post-office of the Confederate States, or the Prussian consul, who is still leading a recruited body of his countrymen in the rebel army. As many of such aliens had been naturalized, and many of the bad men among them had concealed the fact of their naturalization, it became necessary, in order to meet the case of these bad men, to prescribe some rule by which those foreign born, who might not be entitled to the protection of their several Governments, or had heretofore become naturalized citizens of the United States, might be distinguished from those foreigners who were still to be treated as neutrals. This rule must be a comprehensive one, and one easily to be understood, because it was for the guidance of subordinate officers who should be called upon to administer the proper oaths. Therefore it was provided that all who had resided here five years - a length of time which would seem to be sufficient evidence that they had not the intention of returning (esprit de retour) and who should not have in that time claimed certificate of nationality, called commonly a "protection" of their Government, should for this purpose be deemed prima facie, of course, American citizens, and should, if they desired any favor or protection of the Government, save from violence, take the oath of allegiance.