godon's mineralogical observations, &c. 323 



bank. I expected to find the grunstein again in this last, but 

 I found only some fragments of this rock — -an insufficient proof 

 to justify an inference, that these rocks extend beyond the bed 

 of the river. 



We find, in the bed of the Potomac river, several fragments 

 of rocks, which indicate a change in the constitution of the 

 soil running along the upper part of the river: among these 

 fragments is particularly distinguished an amygdaloid (wacke 

 of the Germans) of a dark colour, including globules of 

 a substance sometimes white, sometimes of a fine rose- 

 colour. In the centre of these globules, another substance of 

 a fibrous texture, and of a fine green colour often occurs. 

 This substance seems to be the epidote. These several substan- 

 ces are disposed in the rock, in a very elegant manner. 



Specimens of most of the minerals mentioned in this 

 memoir, are deposited in the collection of the Philosophical So- 

 ciety of Philadelphia. 



No. LI. 



Memoir on the origin and composition of the meteoric stones which 

 fell from the Atmosphere, in the County of Fairfield, and State 

 of' Connecticut, on the l^th of December 1807; in a Letter, 

 dated February ISth 1808, from Benjamin Silliman, Professor 

 of Chemistry in Yale College, Connecticut, and Mr. James L. 

 Kingsley, to Mr. John Vaughan, Librarian oj the American 

 Philosophical Society. 



Read March 4th, 1808. 



Sir, 



We transmit, through you, to the Philosophical Society 

 of Philadelphia, a revised, corrected, and somewhat enlarged 

 account of the meteor which lately appeared in this vici- 

 nity. The substance of this account was first published in 

 the Connecticut Herald, as public curiosity demanded an early 

 statement of facts. Since that, the stone has been carefully 



