A Spanish officer (Colonel Vila) has been residing in this city for some months, and always expressed himself as strongly in favor of my Government, and also seemed so particularly anxious to become intimate with me that I allowed him to go on, and for a time he occupied a room in my house. A short time ago Generals Miramon, Benavides, Cobos, and two others officers of the Church party, or Reckoners, as they are termed, arrived in Brownsville, settled down quietly,a nd commenced a correspondence with Colonel Vila.

They soon became aware that I had in this city 350 U. S. muskets, with ammunition, which were sent to me from New Orleans, and they immediately commenced laying their plans to get them, and to do this they saw at once that I must be drawn over to their cause, and after several prelimowing plan was laid before me: They are quietly organizing a small force on the other side of the river, with which they are to take Brownsville and hoist the Mexican flag, as this would of course make them popular with the Mexicans. They would then cross over and occupy Matamoras. As soon as this was done, Zuloaga, the former head of the party, was to be declared President-Santa Anna to arrive from Jamaica with several thousand stand of arms, backed by a French force who would then cease their operations upon the City of Mexico, and treat with Zuloaga and help him into power. Upon asking what recompense the French would receive for all this, I was answered, after some hesitation, that the State of Sonora would pay them well.

My pay was to be that I should be allowed to hoist the American flag in Fort Brown, they hauling down their own, and delivering the fort and property to any one I might appoint; that all loyal Americans residing in this city should remain undisturbed in their property and free from forced loans. I should also have said that, in addition to the arms, i was to use my influence in sending over a force of 400 armed Mexicans (refugees from Texas) hat I have had control over the past year, and have waited for a word from me to go into Texas, and would be glad to get the opportunity, as there are now but 300 rebel soldiers on the Texas frontier.

My own opinion is that Texas and Arizona are to be included in the price paid the French, but I may be mistaken. I shall not consent to anything as far as I cm concerned, and although this may delay them for a time, still, I have no doubt but that they will succeed, and probably will have commenced before this letter reaches you. They have communication with a French frigate in this harbor, and also with the French army at Puebla. They have a large force ready on the west side of the Sierra MAdre, and all their plans have been laid by a man of more than ordinary ability. Their great drawback is the want of arms to make a beginning, as they could not import them through this port nor into Texas.

I shall remain on friendly terms with either side if possible, and willing form you of the progress affairs. After they work out their own plans, if they desire the American flag in Fort Brown it can be placed there, and when once there I think it can be sustained.

I should write to Mr. Corwin, but most of our mainterrupted.

I am, sir, very respectfully, your obedient servant,

L. PIERCE, JR.,

U. S. Consul.