A Colonel Collins, a native of Georgia or Missouri, has authority from the War Department in Richmond to issue commissions and raise a force for the purpose, and acting under that authority, which he exhibited to Frink, he commissioned the letter as a major in the Confederate Army. Collins did not communicate to him all particulars, but he learned from said Collins and others that many wealthy and influential men in California had urged the rebel government in Richmond to co-operate with them, in order to wrest the southern portion of the State from the U. S. authority, and many of them had bound themselves to contribute the means for accomplishing the plan; some have offered horses, others money, &c. The plot will be matured in Lower California and Sonora, which are filled with secessionists, as is also the case in Southern California. The conspirators expect pecuniary assistance from French mercantile houses. Eleven officers left for Sonora before Mr. Frink started from Monterey, and others were to follow. The plan is to strike in the higher valleys, so as to secure all under them, and because they rely upon assistance from the mining districts. Mr. Frink was ordered to come this way and proceed to California, and from thence to Acupulco, where he is to obtain information in regard to our mail steamers, not only as to the days of departure and number of crew, but also as to the rules, regulations, and arrangements on board, after which he is to meet Collins and others in Mazatlan.

The seizure of one or more of our steamers, laden with treasure, forms a part of the scheme. Frink was asked by Collins if he had money enough to meet his expenses, to which he returned an affirmative answer, believing, as he tells me, that he had. Collins was gratified, because, as he said, they had only about $18,000 to commence their operations with. Frink assures me that on his arrival here he was at a loss to know how to proceed, whether to go to Acapulco, ascertain all the particulars of the plot, names of the men concerned in it, and then to communicate the same to the U. S. authorities, or proceed to the North and advise the Government of what he does know already. He is without means, having consumed on the journey all the money he had. He has concluded, by my advice, to go North quietly and apprise you of the enemy's plans and offer his services to find out the particulars of the scheme, the names of the persons engaged in it, and especially of those living in ifornia who have offered their means and co-operation to carry it out. Collins is represented to be about six feet in heaight, strongly built, black hair and eyes, black mustache, heavy goatee, long, with a few gray hairs, intelligent and energetic.

Mr. Frimk has shown me a letter, dated 1st of May last, from J. Quinterro, said to be the rebel agent in Monterey, to his brother, Antonio J., in Havana, merely stating that Frink is a major in the Confederate Army, and desiring him to inform Frink where Helm, the rebel agent, is to be found in this city. He also says that Frink desires no contact with Americans here. Frink had also a letter from Helm, which he presented, but, as he has told me, did not let Helm know what he had come for. He says that he wants no compensation from the Government, as he has no family, and possesses property in Chihuahua sufficient for his support. All he will require besides his expenses here and passage to New York and Washington is means to carry him to the Pacific. I have agreed to pay his debts here and expenses to Washington at my own cost, subject to reimbursement by the Government if Frink's information is deemed reliable and my course meets your entire approval. The man appears to be honest in his purpose,