Myron Holly, and others, have given me similar specimens, which they represent as being similarly situated, from several localities in the western part of this State.

This secondary sandstone is sometimes more or less calcareous.

I believe it is used for a cement by the Canal Company, which hardens under water.
Will you do me the favor to settle this question?
"On your way to Detroit, you may perhaps, without material inconvenience, collect facts of importance to me, in relation to secondary and alluvial formations.

Anything transmitted to me by the middle of April on these subjects will be in season, because I shall not have printed all the transition part before that time.
"Have you any knowledge of the strata constituting Rocky Mountains?
Is it primitive, or is it graywacke like Catskill Mountains?
I have said, in a note, that, after you and Dr.E.James set foot upon it, we shall no longer be ignorant of it.
"I intend to kindle a blaze of geological zeal before you return.

I have adapted the style of my index to the capacities of ladies, plough-joggers, and mechanics." _March 28th_ .-- While here, I received a notice of my election as a member of the Academy of Natural Sciences at Philadelphia.
_April 28th_ .-- James T.Johnston, Esq., of N.Y., writes on the interesting character of the mineralogy of the interior of Georgia.
The spirit of inquiry denoted by these letters gives but a faint idea of the interest which was now awakened in the public mind, on the exploration of the west, and it would require a reference to the public prints of the day to denote this.