[Inclosure Numbers 2.]

HEADQUARTERS U. S. TROOPS,
Saint Louis, Mo., May 10, 1861.

General D. M. FROST, Commanding Camp Jackson.

SIR: Your command is regarded as evidently hostile toward the Government of the United States. It is, for the most part, made up of those secessionists who have openly avowed their hostility to the General Government and have been plotting at the seizure of is property and the overthrow of its authority.

You are openly in communication with the so-called Southern Confederacy, which is now at war with the United States; and you are orders you are acting, and whose purposes, recently communicated to the Legislature, have just been responded to by that body in the most unparalleled legislation, having in direct view hostilities to the General Government and co-operation with its enemies.

In view of these considerations, and of your failure to disperse in obedience to the proclamation of the President, and of the eminent necessities of State policy and welfare, and the obligations imposed upon me by instructions from Washington, it is my duty to demand, and I do hereby demand, of you an immediate surrender of your command, with no other conditions than that all persons surrendering under this demand shall be humanely and kindly treated. Believing myself prepared to enforce this demand one-half hour's time before doing so will be allowed for your compliance therewith.

Very respectfully, your obedient servant,

N. LYON,

Captain, Second Infantry, Commanding Troops.

SAINT LOUIS ARSENAL, May 12, 1861.

Colonel L. THOMAS,

Adjutant-General U. S. Army, Washington.

SIR:

* * * * *

It is with great delicacy and hesitancy I take the liberty to observe that the energetic and necessary measures of day before yesterday, and reported in my communication of yesterday, require persevering and consistent exertion to effect the object in view of anticipating combinations and measures of hostility against the General Government, and that the authority of General Harney under these circumstances embarrasses, in the most painful manner, the execution of the plans I had contemplated, and upon which the safety and welfare of the Government as I conceive so much depend, and which must be decided in a very short period.

Very respectfully, your obedient servant,

N. LYON,

Captain, Second Infantry, Commanding.