[Inclosure Numbers 3.-Translation.] NEW ORLEANS, August 13, 1862.

Major General BENJAMIN F. BUTLER,

Commanding Department of the Gulf:

I received with pleasure your letter of yesterday, in which you made me the offer to help me out of the shortness of my provisions, of which I spoke to Rear-Admiral Farragut, but some purchases I have made will enable me to wait for the release of the steamer Cardenas (Spanish) of the strange quarantine imposed upon her. Nevertheless, I am exceedingly thankful to you for the courtesy shown me, and shall be most happy to bring the same to the knowledge of the government of my august Queen.

In the same time I should be happy if I could inform my Government that all the Spanish residents in this city are equally the objects of your courtesy, but you have treated in an inconsiderable manner the respectable representative of my Government in this city, threatening him with expulsion because he complied with one of the instructions he had from his immediate authorities. You also desired that the Captain-General of the island of Cuba might send no more vessels to this port. You have answered none of the communications the said functionary sent to you in just and prudent terms. You have ordered that his official correspondence should be opened; because the vice-consul refused to receive the open packages the clerk of the post-office excused himself, saying that was your matter.

You have imposed upon the Spanish steamer Cardenas, on her first passage, an illegal quarantine, in the same time permitting an American ship in the same position to come up, and another foreign vessel also. The said vessel had in her first voyage to suffer a quarantine of twenty-one days, and in the next even thirty days, besides the ruinous and never before seen operation of discharging, when other foreign vessels had only to suffer a quarantine of ten days; you have also sentenced one corporal and one soldier of the marine of this ship, in a case where nobody knew if they or the accusers had been the aggressors; they could not speak English, had no attorney to defend them, they did not know the laws of this country, still the soldier was sentenced to one year in prison, when everybody considered him innocent.

Your conduct in these matters is very different from the kind and friendly manner you showed toward me, and I cannot help telling you how strange it appears to me.

The bad treatment of the representative of my Government, the want of attention to his official letters, the opening of his correspondence, and the sentence of that soldier, cannot justify the friendship you profess to feel toward the Spanish nation which you say has always been a loyal friend of the United States, and I feel that as a Spanish officer I cannot praise your conduct; a citizen I should be happy if I could be of any service to you.

I have the honor to be, your most obedient servant,

JOSE MANUEL DIAZ DE HERRERA.

[Inclosure Numbers 4.] CONSULATE OF SPAIN IN NEW ORLEANS, August 15, 1862.

Senior Major-General BUTLER,

Commanding General of Department of the Gulf.

DEAR SIR: The transport frigate-of-war (of the Spanish marine) Pinta left Havana the 26th of last month in ballast, and with desti-