Report on the projected Survey of the State of Maryland. 9 



vorable circumstances belonging to this locality, is explicable by the 

 first principles of chemical science. Wherever the same conditions 

 shall be found to exist, the production of selenite may be confidently 

 expected. Accordingly, at Hog point on the Patuxent River, where 

 a bed of clay occurs similarly constituted to that on the St. Mary, a 

 like formation of the same substance is found to take place. From 

 the relative position of the two localities, it is presumed that the bed 

 of clay extends across a great portion of the peninsula of St. Mary's 

 county, and may be looked upon as a natural manufactory, upon a 

 large scale, of a mineral substance which can be rendered valuable ia 

 many ways. It may be proper, however, to add the remark, that 

 these masses of selenite cannot be expected to occur throughout the 

 whole bed of clay. They will be found only at its outbreakings, 

 where the concurrent action of the atmosphere and of water will bring 

 about the conditions necessary for their production. 



The occurrence o^ plaster of Paris on the Patuxent, accords with 

 an old tradition in Maryland. It is known, too, that the stucco employ- 

 ed in the State house at Annapolis, is made with sulphate of lime ob- 

 tained from St. Mary's county. This fact had induced an enterprising 

 agriculturalist from a neighboring state to make arrangements for 

 proceeding to the discovery of some continuous deposite of the min- 

 eral. The enterprise was afterwards abandoned, in consequence 

 of a pretended subsequent discovery, that this supposed plaster of 

 Paris had been landed from a wreck of a vessel, coming from Nova 

 Scotia with a load of this article. But the fact of the existence of 

 selenite on the Patuxent and St. Mary, explains the origin of the tra- 

 dition ; and its employment to make the stucco of the State house 

 illustrates one of its useful applications. 



The quantity of the material which may be obtained from the sour- 

 ces just designated, although not very great, is still sufficient to an- 

 swer many valuable purposes. Many cart loads are stated to have 

 been collected, loosely scattered upon the shore, after heavy swells 

 of the river or the violent washings of its banks by an agitated sea. 

 The conjecture is thought a plausible one, that by removing the mass- 

 es of crystals as they become formed, they would be replaced by 

 fresh crops ; and thus almost an indefinite quantity would be obtain- 

 ed. At all events, this portion of the geology of St. Mary's county 

 deserves a minute and careful investigation. 



Besides these deposites of fossils, which have been referred to as 

 occurring in the lower counties on the western shore of Maryland, 



Vol. XXVU.— No. 1. 2 



