191 



This composition approaches nearest to that of albite, excepting in 

 a deficiency of silica, in which respect it resembles the albite from 

 the vicinity of Wilmington, otherwise corresponding to it closely in 

 composition, and agrees also with an albitic felspar from Pennsyl- 

 vania, analyzed by Redtenbacher, in Prof. Rose's laboratory at Ber- 

 lin, (Poggendorff's Annalen, Vol. LII. p. 469,) as shown by the fol- 

 lowing comparative table. 



ALBITE. 



Six miles N. W. of 



Wilmington, Del. 



Booth Sf Boye. 



Pennsylvania. 



Locality not stated. 



Redtenbacher. 



Granular Var'y 



West Chester, P 



Booth dj- Boye. 



Silica, 



65.46 



67.20 



67.72 



Alumina, . 



20.74 



19.64* 



20.54 



Sesquioxide 

 Magnesia, 



of iron, 0.54 

 . ■ 0.74 



0.31 



a trace. 

 0.34 



Lime, 



0.71 



1.44 



0.78 



Soda, 



9.98 



9.91 



10.65 



Potassa, . 



1.80 



1.57 



0.16 





99.97 



100.07 



100.19 



On motion of Dr. Hays, it was resolved that a set of casts 

 of fossil remains, made at the expense of the Society, be pre- 

 sented to Prof. Kaup, for the Museum of Darmstadt. 



On motion of Mr. Booth, it was resolved, that the Curators 

 have authority to permit Dr. Locke, of Cincinnati, to take 

 casts from such specimens of fossils, as in their judgment may 

 not be injured thereby, provided that the moulds be left with 

 the Society and become their property. 



Stated Meeting, June 17. 



Present, twenty-nine members. 



Dr. Chapman, Vice-President, in the Chair. 



Letters were read: — 



From E. D. Ingraham, Esq., dated 10th June, 1842, asking 

 permission to make a transcript of Mr. Breck's unpublished 

 memoir on the Continental Money of the United States, now 

 in the Society's Archives: — 



From the Secretary of the Committee of Physics of the 



* Redtenbacher states that the alumina contained titanic acid. 



